Cab damage

[Patch]

I need some advice. I have my Dad's 1972 K10 short bed truck that he bought new in California. He has since passed and it is in need of repair and rebuilding. The cab has some rust in the cowl area that doesn't look good, the rockers of course are toast, the floor boards need new sections and the cab roof looks like it might need to be replaced. I realize all of this is possible to do, but does it make sense to do it if a decent replacement could be found? There is a lot of history and memories in this truck. He spent countless hours exploring the southern California desert and northern Mexico with his Dad and friends. I think it would kill me to move the project along without having the original cab, but If it's going to cost me 5x as much to get it right......sighhhhh. The only two areas that intimidate me are the cowl and the roof. I know they make replacement roof caps, but that inner cowl looks like a butt to get into. Anyone on here do this type of repair before that has some advice for me?