Welcome to BreitlingSource. The watch is an early Chronomat -
http://www.breitlingsource.com/watch_de ... at_73.html. Servicing is required every 5 - 7 years so if you don't know the history of the watch it might be worth considering a service. Alternatively, if the watch maintains a good power reserve (approximately 42 hours) and is relatively accurate then you may be able to wait a while before servicing.
The service costs are available on Breitling.com - once you select your location under maintenance there is a link to local market service pricing in a PDF so you can see which makes most sense for you.
In terms of straps, the Breitling straps are available from any AD and are very high quality, but there are also a lot of aftermarket strap makers, some of which are reviewed in the accessory section here which may be worth a browse -
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