The 'only' way it could possibly have stayed completely original is if it were stopped from being issued out, and instead, went immediately into storage, and then later in time, sold through one of the programs to a single individual or organization that took more care in maintenance than the military did, and cleaned weapons individually.
If that didn't occur, and it reached the end of the 'normal' supply chain to encounter actual GIs - all bets are off.
The 'big' parts - the slide and frame - 'usually' stay together, but the 'small' parts would wind up in a collective pile and eventually would be assembled at will, until complete, functioning weapons were returned to holsters or arms racks.
The part that actually 'mattered' - insofar as everyone was concerned, was the 'functioning' part.
Back when these were in general issue, spares abounded in the arms rooms and cages - everything from slides, barrels, screws, bushings and grips and 'all' the rest - everything but frames, be cause 'those' had serial numbers and were on the Property Books.
Why were there so many, you ask?
Because of three things:
1. - there was a 'perceived need' with the Combat Arms guys, because their weapons took a beating
2. - accumulation from previous Armorers over decades
3. - no one cared, so no one inventoried
'Then' - replacement frames came to be, in the form of 'Essex' and 'Crown City' frames, and suddenly, all those spares could be bargained for, and a guy then had his own '.45' - probably 'the' number one item every GI wanted to bring back to Fort Livingroom, even though it wasn't strictly 'GI'.
And then one sad day, someone (several 'someones', actually) in the Wisconsin Guard got caught selling spares at the gun shows ( 'lots' of spares - like 'tons' of spares and other 'stuff'), and Uncle Sam was somewhat miffed...
All of a sudden, if you wanted a grip panel, you had to turn in a damaged grip panel with the request, and it had better be the correct one requested - and thus was born a whole new sub-section of 'Property Accountability' in the Micromanagement Division...
But that's a story for another time...
The thing is - there are things to ponder, and then there are things to worry about - 'this' isn't one of those - not if the piece was issued - and neither is the 'correct' magazine, either - magazines were classified as being Class IX items, and were disposable, and in many of the later shooting competitions, the magazines were shot empty, dropped on the ground, policed up, reloaded by the ammo detail and issued out, so keeping track wasn't expected.