My understanding is converting from '67 chrome locking strip style to '68 metal trim style would require a new '68 rubber window seal, new stainless trim and the clips to mount it.
You are correct. I changed my 67 notch over using 68 gaskets, adding the trim clips and sourcing the unobtanium 68/69 notch SS trim. It is worth the work but the trim is hard to find.
