In search of a vintage-appropriate bottle cage and downtube bottle cage clips.

My bike has no bottle-cage bolts/bosses, so the 99% of bottle cages that have a mounting plate with bolt holes don't work. I need a cage with no mounting plate, and the clips to secure it to the downtube.

TA made some nice stuff that I would love to have, that I see occasionally on ebay - but rather expensive.

Without it I'll just be sticking my water bottle in a jersey pocket, I guess.