Looks to be late 70's - early 80's, It looks like a dept. store copy of a Kuwahara or a Webco type frame. I Googled "double gusset looptail" to try to help ya, but couldn't find an exact match. You may have better luck trying that too since you can see the rear drop outs for details like markings/holes. Good luck! You may also want to try the peeps at BMXmuseum.com
[/QUOTE I'll give it a shot, The stamp number's are no help ?? GOOGLE LENS IS MY FRIEND ON FINDING INFO.. LOL I purchase several bikes from a yard sale that day and this was last one laying around , The others sold on ebay...40s-50s Era...Thiis was the only BMX, one, his personal bike..., Crushed it on the others one's $$$ It's much harder with BMX ..HELP..LOL Is it junk???