Hi Gus,
From a pro spray painters point of view, and not to get too technical here, i would basically say that when it comes to any type of paint/dye coating, you will NOT get the same or better durability/performance/wear&tear than any new factory produced vinyl or plastic material.
That said, coatings do have a place and serve a purpose in refinishing plastics and vinyls and leathers that have deteriorated or need color changing, and if applied correctly and properly, do have a reasonable durability to them, but still can't match the durability and performance of a new vinyl or plastic product.
The catch is of course, replacing most or all of the deteriorated (or to color change), vinyls/ plastics in a classic car is quite an expensive thing to do, compared to refinishing the surfaces with paints or dyes. That is why a lot of people choose the refinish path, as it is a much cheaper/easy way to get out of jail so to speak. Worn out/cracked/ distorted arm rests on the deluxe door cards are very hard to repair from a DIY approach, and the better solution is to replace with a new after market card.
So the choice is yours - replacing vinyl and plastics brings a better looking, longer lasting professional end result compared to refinishing your existing surfaces with paints and dyes, but unfortunately, will end up costing you a considerable lot more. It comes down to how deep are your pockets.
One last comment on a technical point to consider - when it comes to refinishing some plastics/vinyls and leathers, you run into a catch 22 situation. That is, plastics and vinyls come in a variety of types and rigidities. When refinishing them, you are chasing the best adhesion and correct film build you can for that surface. Good adhesion can be achieved with using clear plastic primers, and scuffing with the correct grades of sandpapers The problems arise, in the more flexible and stretchy the vinyl substrate is, the more flexible and stretchy the paint or dye has to be as well, to basically match the flex factor of the substrate. If i doesn't match up properly, the coating will eventually break down with problems such as cracking/ peeling etc will occur.
As well, the thicker the coating you are applying, the less flex it will have. That is why for example, you are refinishing a flexible vinyl seat, you need to thin down the paint quite a lot, use flex aid additives, and only apply limited, thin, light coats to avoid thick film builds. Unfortunately, you sacrifice decent film build, and so the finish will tend to wear much more faster. More rigid non flex plastics and vinyls don't present this flex problem, and are more successful in being refinished as such. They allow greater film builds, and present greater durability outcomes. So the more flexible a substrate is, the more problems it brings to achieve a good, long wearing and lasting result. Also, carpets can be refinished with dye products as well, with reasonable results achieved, but again a better result is to replace the entire carpet with a new product.
Hope that all helps,
Greg.
UPDATE! My apologies Gus. I revisited your first post on this topic and reviewed your photos of your interior. Sorry i did not tune into them much at first. However, they do tell a story to me, and the news is not all that good for you in my opinion. You didn't mention in your post if you were going to keep the ginger theme or go for a major color change. In any case, let me assume you are going to stay with the ginger theme. I think it will play out this way for you as you will 1. need to replace the driver's door card as it's toast (speaker hole plus ruined arm rest), and the passenger's door card ( speaker hole). 2. Driver's seat upholstery is toast, and will need replacing (maybe foam inserts as well) 3. fiberglass quarter panels need refinishing or replacing. This can be done with acrylic lacquer or 2pack paints (color match needed here), or better still, can be recovered with ginger vinyl to match the door cards or seats. That all said, the problem overall is matching all the parts up to look uniform in finish, appearance and color. By this i mean that to make it all look uniform and decent, you would have to replace both door cards, and replace the two front seats upholstery and as well replace the rear seat upholstery to match the new front seats. (ie. it's a gamble that the new front seats will match the old rear seat. You might get lucky there or maybe not). It's worth noting that the ginger seat and door card finish or pattern can't be replicated properly with paint coatings as such . Trying to color match the ginger solid color can be very tricky as well, and would need to be carried out by a pro painter. It's also worth noting that in many ginger interiors, original or not, you will see noticeable color variations with different parts that display a solid ginger color finish. That's just the way it goes for our cars i'm afraid. See my pics below). In that regard, color uniformity can be achieved by accurately color matching a particular part, and then refinishing all other solid color parts around the interior to match. Your cracked dash pad may be able to be repaired, color matched and resprayed with lacquer or 2 pack paints, but i would need to see up close pics of the crack to make a final call on that, as adversed to the need to replace the whole dash pad as such. But best bet IMO, would be to bite the bullet, have a chat with your bank manager, and replace the parts i have suggested above, plus refinish all your solid color parts for color unification. Which ever way you decide to go, all the best with the project and end results.