Well its a frankinstein gun so input may be sketchy. What kind of internals? Colt barrel? para's receiver parts? In the long run I'm looking at trouble. Para Ordinance does not always run there 1911's true to spec so simple things like replacement grips, grip safeties and other upgrades will be harder to do. Also Para's have been junk in the past. They used to be really good but depending on age, your looking for trouble. For that kind of money you could get a GI spec rock island knowing you can upgrade parts with no real trouble.
Hard to say without more info but if it works its worth $400-
I built one with a Para frame & Caspian slide- Colt frame & Essex slide & several others with the " frankinstein" effect--- HOW its built is more important at this point IMO.
When Para Ordnance first came on the scene they only built and sold their large capacity frame, you were required to acquire your own slide and go from there. The configuration of Para frame and whatever slide is not unusual, but I would make sure it ran properly before I invested any funds in it.