Who did you take this to and where are you located? Depending on what you’re willing to pay, there is no reason you can’t have the watch fully restored without replacing the movement. Bucherer watches from this time period used common ebauches. A competent watchmaker will be able to source and make replacement parts as needed.
Run, don’t walk, from whoever this watchmaker is.
The case, if you want, can be restored to as new with laser welding and use of a lapping machine (note: this is different from what most call “polishing”). It is important that if you do proceed with case restoration that you go to an expert restorer skilled in these methods. Jewelry/watch shops and even the vast majority of watchmakers and official service centers will simply polish the watch on a buffing wheel, which will not restore the factory finish and will permanently soften all the crisp edges. A good case restorer, on the other hand, will be able to restore the sharpness of the edges, preserve factory contours, and return the finish to indistinguishable from factory new. This is particularly important on a very angular watch like yours.
The trick is, as implied above, case restoration is a niche specialty and you also need the services of a good watchmaker to work on the mechanicals. If you are in the U.S., two of the absolute best in both respects are Zimmerman in Pennsylvania (@zimmermanwatchrepair on IG) and Alex Cianni in Los Angeles. Zimmerman is probably your better bet. Cianni is mostly focused on high-dollar, rare Pateks. Unlike other restorers, they are able to precisely moderate the degree of case restoration—so you can fill-in dings and restore edges, but keep all the hairline scratches and patina appropriate to an older watch. The downside is that Cianni costs an arm and a leg. Probably overkill.
LAWW and Rolliworks in California are two of the world’s best when it comes to case work, but they mainly focus on Rolex and are not as deep in mechanical proficiency. They’ll only do non-Rolex work on a case by case basis, but I would trust either if they say your job is doable. Conversely, Rikki at Time Care in Florida is one of the most trusted independent watchmakers for mechanical servicing in the States, but he is not a case restorer.
If in Europe, there are a plethora of case restoration experts across Italy: Time Lab in Milan, Giancarlo Martini in Parma, and Il Menzerno in Rome, to name some of the best. However, Ro & Ro in Austria would be my recommendation. They are the official service center in eastern Europe for many of the big brands, including Audemars. More importantly, they are enormously proficient in both case restoration and mechanical work (including part fabrication). The Italian options tend to be more focused on case restoration alone.
Good case restoration work without the need to fix catastrophic damage is generally in the $300-1000+ range (depending on the labor required and skill/reputation of the restorer). However, I suspect you’ll be on the lower end of that scale, as your case is relatively simple.
Mechanical servicing of a basic movement should be around $200-300, barring the need for intensive fabrication.
@TheFoo Thank you for this educational and detailed answer. I'm very pleased to learn that the mechanics can be restored. That will certainly help when dealing with local watchmakers.
Unfortunately, I'm not in the US or Europe so I'll have to see if I want to wait until I can get to Europe or go with a local service center (an official service center for most high-end brands).
BTW, are you familiar with any restoration experts in France? that's most likely will be our European destination probably towards end of 21.