What adhesive do I use on vinyl Top ?

Sorry I don't know modern paint gun tip sizes. I have a upholstery shop
and spray contact cement thru a Bink's 2 1/2 gal pressure pot I bought 30 some
years ago.
If I remember correctly the tip I use was meant for spraying undercoating.
This has been working for me my entire career.
If you just get the largest tip you can find it will work. I believe the modern clear coats
take a large tip.
You can clean up a gun after using it for glue but I would just buy a cheap throw away
unless you plan on doing more than 1 top. The cheaper the better for something like this.
It would likely ruin a quality gun. Bink's 69 is the model I use. You should be able to get one cheap on eBay they are so out dated. But you wouldn't need one that good to get the job done.
But it may be the cheapest thing you can find?