welcome to the forum & congrats - the 817 is a superb and rare watch indeed, but "from abroad" doesn't really tell us where the watch now is ?
sound advice to stay as far away from Breitling's official service as possible- as long as you aren't in tghe US, there the Breitling Vintage service is done by the Heists of horologicalservices.com, good but slow and quite expensive.
but what you describe above can be done by any competent watchmaker - if you have no service records, the watch should be professionally serviced and regulated before you use & wear on a regular basis anyway.
so if you tell us what country (or continent) you are located in, we might be able to help ?