Not sure if we’re related. I was born and raised in Maryhill in Glasgow. My dad’s dad was Archie Forrest from Glasgow and he won the Irish sweepstakes in the 1930s.
The only Archie (Archibald) I'm aware of in my direct family was born in 1855 in Biggar, clearly too old to be the same Archie you refer to.
I've done some research for other of my Forrest contacts and have details of at least a dozen or so Archibald Forrests, but again, they are all much too old - some going back to between the mid 18th and mid 19th C. Could be you are descended from one of them if the name was passed down through the family.