RWS repair

Hi folks 
I'm trying to assist by sister with an air rifle that belonged to her late husband. I know some things about guns, but nothing about these airguns. I understand it was a fairly expensive rifle when purchased. Local gunsmiths have no idea. It is a RWS TX200SR. Anyone know who repairs these rifles, and any ideas as to its vaule. She also has a Model 54 Air KIng that seems to work fine. Any value idea or where she could attempt to sell them.
Thanks to all in advance.
 
A little info on your Air Arms TX200SR: http://www.pyramydair.com/blog/2006/04/air-arms-tx200-part-2/
not too helpful "valuing" your TX, but explains some of the differences between it and the "regular" TX.
My local gun shop also knows nothing about air guns, but they have sold used guns in the past on consignment for the owners. Your sister may want to consider that as a possibility. I know I visit gun shops (more often than not) looking for that old airgun that's been on consignment for ever, and they're looking to get it off the shelf.
 
Yes, that first rifle you mention is an Air Arms gun, the second rifle was made by Diana (M&G) and marketed in the US by RWS who have ceased trading. Most Dianas in the US have the markings for 'RWS' (official importer for many years) most spring gun smiths would have no trouble working on that model.

The SR variant of the AATX200 is somewhat of a rarity as it was a short production run - which might be of special interest to a collector!

For values have a look at the sales sections on places/forums like the Dianawerk Collective, Yellow Forum and Gateway To Airguns Forum - they have a suitable 'back history' of sales prices. (This forum is rather too new by comparison).

In my experience the best prices are achieved on dedicated WWW sites like those above, 'Gun Shops' sometimes suggest comically low prices (being polite!) esp. if they think the seller has no interest in airguns.