(1) Military mark query & (2) CAF valuation query

(1) Can anyone please advise if a letter 'A'. in a circle, printed on a watch dial is a military mark and if so what does it mean? I have looked in Ziggy's book but there is nothing listed. The mark appears on a WW2 'no makers name shown ' chronograph wristwatch with a Valjoux movement and described as if a Royal Naval issue with provenance papers from original owner to whom issued.

(2) What would be a reasonable dealer price for an original WW2 CAF Longines ? I have seen a few on Ebay c. £600 ish and have seen one in a dealer reduced to £800 ... would £800 still be a bit OTT for an original if it had a 15.68z movement?

Thanks

Duncan