No that's not an AYA Yeoman (they are a 'nail' not a gun).
Yours is no nail, and someone paid Westley Richard's about 5x the cost of a 'Yeoman' to
make new barrels for it.
Yours is most likely a Birmingham boxlock from the 1950's, I've seen 100's like it, but that
said it's only worth £350>£500 on a good day, nice gun! Make sure you use it!
AndyF
Seconded