What crown and lugs are they that are on the ebay Harry Quinn we've discussed? The one John guessed at as 73 or 72.
I have a similar looking R.J.Quinn also labeled Quinn Bros. bike with the same lugs (without the cutouts) and the same crown finished a little differently on the outer edges.
My R.J.Quinn also has the front der braze on on the down tube that I think of as indicating early 70s, but it had (very likely original) Shimano 600 "arabesque" group which I thought suggested much later 70s. Maybe not?
The CR archives tell me that there were several Quinn brothers, Harry the most famous and successful.
Little Rock Canyon, Utah