Only problem I see with taking it to students is that the job is only going to b as good as them, I know that goes for saying with any welder. I have the same trunk problem in my 72 coupe but found I guy my dad knows thats a good mig welder, some cash up front and a case of beer after lol. But as being with any student they are still learning which in the long run could end in warped sheetmetal and a whole new hassle. I could be wrong just a thought. Looks like its coming together for you though, at times you sound stressed and a little aggravated. Older cars are problems thats part of why we take them on, expecually if you have a love for the model, to take something busted and breath new life into it, to bring it back from the brink. Take a breather, have a beer, when you've gathered your patients have back at it. As far as the vinyl I would take the hit of having it on for the pride of saying I have a rare model but truth be told it comes down to your taste...are you wanting it for the boast factor or the love? If for the love of the classic stang go with what will make you grin ear to ear when you look at it.