I got the truck back (at a friends house as he has more tools than I). It rained a lot today but I was able to confirm where rain was coming in. It is coming in thru 2 spots on the front windshield. I will try to fix it without replacing the seal first. But in the case I need to replace the seal, which one of the attached gaskets is the one that I need. I am new to this model truck and not quite sure of everything related to them.
It is still setup as a 6 volt system, but trying to figure out what all needs to be done to go ahead and convert it to 12 as I know this will be better in the long run.