Pinching a page from a comment by Mark on the '63 Meteor, here:

Seems to me a lot of the 'custom' bits in kits of the era looked familiar to me - I know this was a 1:1 practice for wheel covers and trim items before there was a robust aftermarket to supply them. Sometimes these were called out in the instructions, sometimes not. Thought it might come in handy to make a list, cos you never know when you will need 'em.

I'll throw out the first pitch - '63-4 Mercury seems to have the '61-2 Cadillac deep draw wheel covers and the '58 Bel Air taillight bezel - and the '62 Ford optional covers look a lot like '61-2 Buick Electra.

Others... let 'em rip.