I am really not sure what to tell you. I don't have much experience with the FEF 390 movement but after a brief google search of "Tudor FEF 390" a couple of the hits identified parts availability issues with the autowind mechanism. In most cases, I recommend thay you search google and see what comes up. Use the brand, calibre and words like service, parts available, problems, issues, etc. That is what most of us do. Here is one related to the 390.
https://www.watchuseek.com/threads/vintage-tudor-subs-serviceability-of-cal-390-vs-eta-2483.4267346/
The Tudor Prince watch may be fine, but on the other hand, there may be parts with borderline wear, that will give you grief. Until your watchmaker looks at it, you have no idea. The autowind systems on watches have moving parts that wear and it is not uncommon for rotor bushings/bearings, or reverser wheels to wear out and need replacing.
My Solar Aqua is the same case size as the Tudor that you have linked to, except mine is a manual ETA 1182, which has fewer moving parts to wear out. In a 1952 watch, that is a plus for me.
I don't just rely just on the internet. I was looking at an old Rolex early 1960's Air-king a while back and I went so far as to email my watchmaker to see if had many issues getting parts for this movement and he indicated that in most cases, he can get what he needs.
If you are looking at watches from the 50's and 60’s, some of the good movements I would have confidence in are:
OMEGA: 5XX, 7XX, 2XX, 6XX are all good. For a daily wearer, 3xx bumpers may present parts availability issues.
Rolex 1520, 1530, 1210, 1220 are good
Variety of ETA, A. Schild. And Felsa movements will be found in many secondary brands and are fine.
Perhaps someone can suggest the good Longines movements or ones to avoid, if any.
Good luck with the search and don't be afraid to use google to pull up lots of discussion threads from the various watch forums.
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