There were templates back in 3.5 that allowed you to add 2-4 extra arms to a golem for a relatively decent cost. Looking over the modifying constructs rules, I don't see anything about adding more limbs. What if I want a centaur flesh golem? How about a spider stone golem? A two-headed iron golem? What's the new cost? Do they gain new abilities (trample, two breath weapons, multiple attacks) like their original versions? Where can I find Pathfinder specific rules for this?
If it's just a simple "you missed it here" or "you didn't quite read far enough", then that's cool too. Quick apologies if I did, but still grateful for having them pointed out. If they don't exist at all, then that's unfortunate.