A rough draft. Comments welcome.
I am not going to expand this to a full class entry, because the likelihood of one of my players taking it is pretty low - if you have Player’s Companion, though, this should be sufficient.
HD: d4; after 9th level, +2 per level.
Prime Requisite: INT.
Build Points: HD 0, Fight 1 (thief), Thief 3 (10 skills).
Weapons: Restricted (2 customs).
Fighting Styles: Two-Handed Only (1 custom).
XP: HD 0, Fight 500, Thief 700. After 8th level, 100,000 per level.
Thief Skills: Open Locks, Find Traps, Remove Traps. (7 customs).
Master Craftsman (3× one Craft proficiency).
Attention to Detail (grants +2 on all proficiency and thief skill throws) (3 customs).
Design, Build, and Repair Automatons (3 customs).