Hi all ,first time poster looking for some imformation about a lock i recently found while cleaning out an old irish post office.Its of rectangular shape approx 2.5" by 1 3/4" by 1/2" thick.A metal tag is attached stating (2/6 reward will be paid to the finder of this pouch at the post office)On the back it is stamped GPO NO.6 CHUBB LONDON with a serial no.E3476.Any imformation would be appreciated.