Treasure map found in frame!

just got off the blower to me old man. He said he didnt put it there so it must have been when it was built for him.
He did say that back in the day they used to write their name and address on a bit of paper and hide it in a tube/handlebars so that it could be used to ID the frame if it was ever pinched, maybe it was some random way to do just that?
everyone with a handbuilt harry quinn go and chop yer chainstays off to have a look

Probably used to put his own address in each one. Reclaim, re-sell, reclaim, re-sell, etc...