One of the most frequent requirements we're getting is to provide assembled repair kits for HP41C. The problem is that we depend on getting used, destroyed HP41c calculators to peel off the old flexible circuit, clean it and file off the rivet remains, and adhere the new flexible circuit to the plastic base. The issue is the first part - getting the part to perform the work.
Once you have used the part, your calculator cannot work - so you can only get it from damaged calculators that you're going to use as part donors. This is the reason that we don't get more of these assembled repair kits.
On the other hand, it really saves a lot of time and patience to avoid folding and collating the sticky flexible circuit - I always wonder whether it is going to work properly once finished. The assembled part takes the doubt off the process!
I will post here a message once I get more assembled repair kit parts.