Bucket seat tracks

Hi everyone
I'm looking for bucket seats for my '69 Dart as it came without. A pair of what are claimed to be '68 Barracuda buckets have come up locally minus the tracks; and are factory hemi fixed brackets which I'm not interested in long term. I've read alot about the inter-compatibility of '68 and '69 seat cores/frames and tracks and wanted to get some confirmation to what I've read if I can please. Am only considering '68 and '69 components as I understand there was a lot of same same btw these two years.

1. Are '68 and '69 A-Body seat cores/frames identical across years and Dodge/Plymouth ?
2. Are '68 and '69 A and B-Body seat tracks identical ? If I could locate say a set of B-Body '68 tracks, will they fit a set of A-Body seat cores ?
3. Is there any core/frame difference between seat trims ? My trim is Rallye and the seats for sale are trimmed as Standard and I am hoping I can get a set of Legendary Rallye cushions on the frame no problem.

Thank you for any help here.