I think there is only one type of flat top terminal pin available unless someone has a corner on very old NOS parts. The original three slot pin retainer was bakelite so they are rare now days. The repro black plastic types may be problematic with the current pin fit but I haven't tried any yet. Even the stamped plug pieces are questionable but addage, "if there is a will, there is a way" fits here. I know the next time a fit up a set of headlamps, I'll have to deal with this problem. Your not the only one that has problems with this stuff.
If you have decent harnesses that just need the right flat top pins then you might try just replacing the pins. I've ground pins down to extract them without shortening a wire. If it isn't a length problem then just cut them off and install a pin that will work. his link is the type of connector pin I'm referring to. They require soldering.
https://www.snydersantiqueauto.com/product.htm?pid=976449&cat=41726