There's more to consider with Gril tanks; the location of the rear brace inside the tank is critical to fit mid 50's to date and prior to mid 50's, and middleweights a little ignorance I recently learned, the hard way. Bought a coach green and white that's painted no different than 40-50's yet, in mid 50's Schwinn removed the cross brace on girls top and bottom bar. I.E. if you're fitting a girls without the older cross brace in-between top and bottom bar (mid 50's and up) It doesn't matter, but, only pre 'new style' of pre mid 50's will fit this era. For Schwinn's 'new style tank' ( made for No top and bottom bar cross brace) Schwinn lowered the position of the inner tank's rear bracket and if you're fitting girl frame with frame brace, (50's and below) or for my 48 and 53 girls unless you reposition tank's rear bracket,, cut off and refit, weld, Ur screwed. .
Hence with this tank, it could be Opel or Flamboyant green yet just because it may be a 'new style' in either color, maybe a 54 opel, maybe a post 55-60's Flamboyant. . The location of the tank's rear bracket is critical. I.E. now I know, 'the hard way' the coach green and white, (Ivory) girl tank I bought recently, will only fit, circa mid 50's and up Aprox, 56-8- 60's without bar cross brace.
