The conversion below is for both Blood and Treasure (as it currently stands in my mind) and Swords and Wizardry, with S-n-W stats being behind the slash where necessary.
Huge Construct, Intelligent, Lawful
Hit Dice: 30
Armor Class: 27 / -8 
Attacks: 2 spinning blades (2d8), 6 projectile spikes (2d8, 120’) and lightning bolt (10d6, 300’) or sonic blast (10d6 + deafness, 60’ cone)
Move: 60 (Fly 200) / 18 (Fly 30)
Saving Throws: F8, R2, W2 / 3
Special: Summon iron golem, +2 or better weapon to hit, regenerate 3 hp/round, resistance to fire and cold (50%), immune to polymorph, petrification and illusions, blindsight (500’), telepathy (1,000’)
Spells: At will – Displacement, ethereal jaunt, greater dispel magic, greater invisibility / Dispel magic, invisibility, etherealness (as the potion)
XP: 38,000 / 39/10,100
Anaxims, or God-Machines, are massive constructs shaped something like beetles and are as large to an iron golem is as an elephant is to a human being. In place of mandibles that have two spinning blades on iron arms and their bodies are studded with six massive spikes that can be launched at enemies up to 120 feet away. They can also emit lightning bolts and sonic blasts. Four times per day, an anaxim can summon an iron golem to fight by its side.
Anaxims might be the product of titans or hordes of lawful creatures like formians. They are created to smash the forces of chaos (in a final, end of Law vs. Chaos way) or guard the secrets of Creation.
The Regenesis campaign pits the adventurers against a secret cult dedicated to re-creating the universe. The current universe, they believe, is tainted by chaos and thus not perfectible. They wish to create an anaxim and set it upon the forces of Law, smashing the machinery of creation and allowing the universe to collapse in on itself and, in their belief system, be recreated from a single, perfect mainspring. Of course, they are insane, but that doesn’t stop them from being dangerous.
BASIC: Basic adventures pit the adventurers against the foot soldiers of the cult. To create their anaxim, the cultists have struck out in search of pure metals and master smiths and engineers, enslaving them. Each individual cell of the cult is responsible for a single part of the finished anaxim, as guided by a group called “The Divine Architects”. Perhaps the ultimate basic adventure would have the adventurers penetrating the slave factory of one cell as they prepare to place their part of the anaxim in the hands of a visiting, extra-planar Architect.
EXPERT: The expert adventurers force the adventurers to strike out into the wilderness to attack other cells of the cult. Perhaps there are three key factories all trying to produce a single part of the anaxim, and at least one must be stopped to slow down the cult’s plan. Golems of various kinds should come into play at these levels, along with conspirators of the cult – sages, magic-users, nobles, etc.
MASTER: The master level adventures involve moving beyond the material plane. The plan of the cult, which is spread across the cosmos (i.e. not only on the adventurer’s home world), has put the Divine Architects (formians) in conflict with the polyhedroids who maintain the mystic gears of the cosmos. A perfect mainspring has been stolen, and the cosmos is grinding to a halt. The adventurers must find the clandestine base where the various parts of the anaxim are being assembled, for it is hidden in a pocket dimension somewhere in creation.
EPIC: The final adventurers involve an assault on the pocket dimension of the true powers behind the cult and the Divine Architects – a band of rebellious titans who seek the cosmos’ destruction for their own purposes, as each believes he can create his own little universe – a multi-verse, one might call it - with he or she taking the role of Creator. The pocket dimension houses a small world (about the size of an asteroid), and deep within this world sits the anaxim, ready to be activated.
A couple notes on Blood and Treasure ...
For Armor Class conversions (SRD to BnT), I'm using the following formula:
AC 10 to 18 = keep the same
AC 19-20 = 19
AC 21-22 = 20
AC 23-24 = 21
AC 25-26 = 22
AC 27-28 = 23
AC 29-30 = 24
AC 31-32 = 25
AC 33-35 = 26
AC 36-38 = 27
AC 39-41 = 28
AC 42-44 = 29
AC 45+ = 30
Determining XP in Blood and Treasure will (at the moment, I might change my mind) be done as follows:
For monsters with no special combat abilities, XP = HD x 10
For monsters with minor special combat abilities, XP = HD x 100
For monsters with major special combat abilities, XP = HD x 1,000
And no, I haven't yet figured out what will count as minor and major special abilities. Spells of 0 to 4th level will probably be minor, spells of 5th level or higher are major; resistance to damage (i.e. half damage) will be minor, immunity major; only harmed by silver weapons minor, magic weapons major, etc.
The saving throws are just the number you have to equal or beat on a d20 roll for monsters. Characters would be adding the appropriate ability bonus (constitution to Fortitude saves, dexterity to Reflex saves, wisdom to Will saves). If the save is considered "difficult" - for example, if saving against a creature with 5 HD or levels more than you or because of some extenuating circumstance determined by the Referee, there is a -5 penalty on the saving throw. I'm trying to keep bonuses and penalties to a bare minimum in Blood and Treasure.
I'm going to cap monster Hit Dice and Armor Class at 30. From Kobold to Orcus (or Anaxim), I think a range of 0 to 30 is sufficient. Character levels run from 1 to 20.
Oh, and yeah, I'm still working on Space Princess (art is being produced by Jason Sholtis as we speak, and it rocks! I need to write a sample space fortress ...), 1800 - American Empires (holding pattern until Space Princess is finished) and Action X (holding pattern until American Empires is finished - oh, and I think I found a font I like for the title today!). Also almost finished with Hex Crawl Classic 6 (this weekend for sure), still working on NOD 12 and I should dive into Rappan Athuk at some point soon. Busy and happy!