Here is a ebay auction with a good example of the differences between repro and genuine oil filters. https://www.ebay.com/itm/NOS-Ford-Rotunda-Oil-Filter-R1-A-Shelby-Cobra-260-289-427/254034089067 .This is a 65 filter but similar criteria can be applied to the 66-70 repro filters also. I will post the sellers pictures for posterity.
Makes you wonder, if you're going to go through the effort to make a sleeve over, why not make it more dimensionally correct?
What about comparing to the black assembly line oil filter for 65? Is the repro a match to that or is the service filter a match?
Thanks for posting, Bob. It has been a long time since I saw a reproduction filter of such poor quality. They seem to be much better now, but the lip of the sleeve on the best ones can still be seen under close inspection. And I'm not sure the dimensional differences are always so great — I've seen various NOS filters of (at least) slightly different size. I'm guessing multiple facilities might have been involved in making them, or perhaps the tooling varied from time to time?
The later ford fl -1a is a little shorter than the fl-1.