A Facebook message:
"Hi, I have found a set of pistons in my grandfathers garage.
Could someone let me know what model they belong too and if anyone would be interested in them? "

Any interest please PM me.

According to the info I have, and based upon the box saying "2-1/2 inches bore" they are listed for a 1934/35 1203cc engine and/or an LD10 1287cc engine.

Hope this helps, but check further!!

Very helpful, thank you Stan