RoseB, firstly welcome to the Stovebolt.
This seems to be a common conversion on account of availability of good serviceable,original 'burb' parts.
As Billyray mentions any good glass shop can template and cut new glass for you.
The most common seal to use is called Claytonrite rubber.
It's exactly the same seal used on the back cab glass of AD pick-ups and COEs.
This has a black rubber lock strip,or you can go to a chrome look insert if you prefer the
'Deluxe' look.
If you make the templates yourself,the glass shop will make the necessary adjustments to the glass size.
Claytonrite is an 'H' section so the glass has to be 1/4" (approx) smaller than the aperature itself.
The 'bunching' you refer to is caused by the tight radii.
1/4" x 1/8" Claytonrite should work and any bunching should disappear once the lock strip is installed.
Gentle heating with a 'hot air' gun sometimes helps too.
I hope this info is of use to you.
