Airsporter "S" MK1 1979-1983 Valuation to sell please

[Sakerman]

We had dinner at the in laws last night, my farther in law has just had a hip replacement and at the age of 71 has decided to sell a couple of his guns. One is a BSA Airsporter, serial number GM36219 which, according to John Knibbs, makes it an "S" MK1 in .22. Its in lovely condition, not mint but very very good. It was serviced by a local gunsmith about 3 years ago and has not been fired since. Would some one give me an indication on a possible sell value? Should anyone like a couple of pictures please let me know.

Thanks in advance.