The outside handles will appear to be very similar, BUT the main difference will be the specific body contours the handles touch on the outer door panel itself. Those contours/curves need to be exact so the handle looks like it belongs there.
IF you have the correct part numbers, you can (free download) download the 1970 Chrysler parts book at
www.mymopar.com to verify what fits what, according to Chrysler.
It might be that the 1969-71 Polara/Monaco handles are the same, but nothing earlier than that as the body shell changed in 1969, which rules out the 1968 Dodges as candidates.
As you will find, there are lots of things in repro for A,B,E-body Chrysler products. Few specifically for C-body Chrysler products, except some of the mechanical stuff like fuel lines on the engines, typically.
Personally, I like the OEM outer door handles, rather than the repros. Why? The OEM production items, when looking at them under a strong light, will reveal the "sand scratches"/polishing marks on the original chrome finish. Repros do not have those items. In other words, the repros look too nice compared to the OEM items. IF you know what you are looking at, you can spot the repros from a ways off.
Enjoy!
CBODY67