The cap and the rest of the parts are the same as 100/6-3000Mk1 and 3000 mk2 (Big Healey) I'm sure I have at least one set lurking around here..... in fact the Healey parts are the same for all of the Tiger stuff.... Mk1-Mk2... it's the bottles that are different. the Mk1/mk1a bottle is dimensionally the same as the the 100/6 through Mk2 Big Healey... the bottle on the Rootes cars is different due to the embossed Rootes logo. The cap is identical. same for the Mk2 w/s washer bottle... while the bottle dimensions are unique to the Mk2 Tiger, the lid is the same as the earlier cars