Any old steel frame will generally work. Take your time though. I see a lot of guys do very poor prep work of the metal before starting their lug wrapping. Don't be in too much of a hurry.
Sourcing appropriate Aluminum is also relatively easy even if you don't want to go to a supplier who provides actual frame material.
You can get stuff that's very close to the same dimensions at least to the point where someone can ream the headtube and seat tube and thread a BB shell.