It’s one thing to just weld them, but it’s not enough. I want to put a Spiral Sallet on the Engineer without his default helmet clipping!
Oh, just put your crosshair over the model and type this into the console:
ent_fire !picker setbodygroup 1-9
Play around with numbers 1 through 9 until you get your desired version of the model.
This also works with every tf2 class model, just for reference.
Scout: hat and headphones
Soldier: helmet, service medal, and rocket in his hand
Demoman: his little smiley face on his crotch, his grenades, his feet
Heavy: hands or no hands
Engineer: helmet, gunslinger, no arm
Sniper: hat, arrows, and darts (Sydney Sleeper)
Spy: Different masks