I built one when Para was only selling frames. Yes that was a long time ago!
I should say I tried to build one. I took the parts from my working 45 Colt put
them on the Para frame. Would not function! Put part back on Colt, Colt worked fine.
I tried this several times. With the same results. Yes I know what the definition of insanity is!
So I took it to a gunsmith. He got it working just fine. With all new 1911 parts.
If you have some gun-smithing skills! Which I do not.
I can tear them down and put them back together. But fitting parts. Not my thing.
As you know even drop-in parts, Are not all ways drop-in!
One other thing that I found with P-13(old style mags) The springs Para uses
are poor to say the lease. I changed mine over to Wolf Springs.
IMHO the mags work much better!
Good luck! Would love to know how it goes.
As well as a picture or two of the build.
PITA45