[Karl Wescott]

I discussed the issue with Bob many years ago. His stand, at the time, was that his original pattern was not vented, and the costs to tool a non-vented version were not warranted by potential sales (and some costs and technical challenges as its not easy to seal the lock).


The other issue here is in the days of explosion of restoration/rodding popularity (late 1960's through mid 1980's), that the "common" parts store knowledge of fuel cap interchange was the "green bible", which shows the same fuel cap 1932-48. By the time it was published Ford had apparently forgotten or did not care about fuel spillage on the earlier cars. And neophyte parts vendors were "led down the garden path".



Bob also has a history, of once he has published an interchange, that HE is "correct" and has rarely, if ever, retracted or modified his interchange. Note that Bob is also VERY careful in his research so the vast majority of his interchanges are correct, though some are not.