Re:
Ok, yes it maybe less troublesome to go for some rigid steel forks. To get some original green ones that somebody has lying around will be some kind of miracle.
So, pick up any old steel ones, spinner/tange if possible but they are all good.
26"....steel...1.1/8" is the easy bit, pocket money stuff. Then you need to determine the steerer length you need.
Marin measured the frames centre of bottom bracket to the stars and stripes sticker on driveside of frame, if sticker missing just go centre of top tube.
iirc...
15.5" = 134mm forks
17.5" = 153mm " "
19/20"= 183mm " "
Don't worry about headset stack height too much. Although i'd go as low as poss, maybe a ritchey as they seem to be low, meaning you can add spacers to get it right, where as having a steerer too short will be a problem to solve with a specific headset stack heaght.
