64 Dart Vert Top interchange and questions

Kidd said
1964 Dart convertible top, will it fit other makes like a Valiant? or just maybe 63/66 Darts?

The top and top frame is just the Darts

Kidd said
Is the back seat bottom convertible only? It looks like it.

Yep as is the seat back which will fit both Dart and Valiant. Same for the convertible lift covers

Kidd said
Are the side windows convertible only?

Yes and IIRC Dart fits Darts and Valiant to a Valiant

Hope this helps!