Windshield Questions 71 Scamp

Hi everyone,

I'm looking to remove my windshield to remove rust from the channel / fence, and I have done a few searches on how to do it as well as service manuals. The manuals are ok (doesn't mention scamp in the 71 plymouth manual, so i looked at dart) and seem to be in line with the majority of what people say:
- remove glass, then rubber, clean it up
-install rubber gasket, then work in the glass

my questions are:

-Is butyl sealant better then 3M Bedding and Glazing Compound?
-And, since its a 71, do I need a locking strip? some gaskets I see don't have an accompanying locking strip to buy. The 70 Dart service manual says to put a filler strip in the bottom, is that the locking strip?

Thanks guys for any insight :)