I am thinking of purchasing a pair of bucket seats for my 70 Dart.

How do I tell if they were from a 1970 Dart?

For example, I want to be sure I am not buying a set of dart tracks with E Body seats bolted to them.

Any photos will be appreciated.

The '70 & early '71 bucket seat frames are the same between A, B, & E - bodies.
They have the diecast hinge covers with seat release button, mid-'71 the button became part of the seat back.
Foam & covers are different between the body styles.

Dart buckets - 1970 Trim Book at Hamtramck-Historical

& the '70 Dart bucket from Legendary's site

Thanks. This is very helpful.

Was the button in the hinge cover for all 1970 A,B, and E bodies?

Yes, All '70-early '71 bucket seats used the diecast hinge cover, there is a potmetal rivet that attaches the button to the cover that is often broken.

a-body seat tracks (I believe '68-'75? until catalytic converter floor hump) - at some point ('73-'74??) the inside tracks were redesigned & the positioning locks were removed

Thanks Dan!