[mrerick]

All this is speculation since beyond what Gerben provided above, I don't know of a detailed description of the refurbishment process. But... put yourself in their position right after the war.

As weapons were captured and recovered, they were brought to collection points and all went into a pile, often sorted by type of firearm. All the Lugers together, all the P.38 pistols together, all the K98 Rifles together etc... Sometimes in large wooden boxes. Pictures of this are available.

Once they were transported to a refurbishment depot, they would likely be taken from the box, given a brief inspection and then sorted for processing. At that point, damaged weapons would likely be field disassembled and the parts put into sorted bins. Luger toggle trains together, Luger canons together, Luger frames together, damaged subassemblies to disassembly bins. Once those were stripped to individual parts, those were sorted.

It's logical that complete serviceable weapons would be kept completely together, especially if they were captured new in their shipping boxes.

We know that guns like Lugers had to be hand fit.

With limited tools, space, labor and skills it makes sense that rather than hand fit used parts together, the refurbish gunsmiths would try swapping a number of different donor parts to see which ones fit best, made the action most reliable and the trigger acceptable and safe. That would logically be done by swapping available parts and subassemblies until you got "a good fit" instead of modifying donor parts to make matching ones fit.

Once you had a proper fit (regardless of the source of the parts) you sent it on for dip refinishing, new grips as needed (since the bakelite and wood grips would probably be damaged in handling) and proof testing.