You have a lot of factory choices because the 73-79 model base is interchangeable. I think you have six models in the 100 series, and each one differs by the amount of trim and get progressively fancier. It goes like this (I think): Base, Custom, Sport, Ranger, Ranger XLT, and Ranger Lariat. The choices get progressively fancier over the years. For example, the Ranger Lariat package was not available until 1978. And you also have packages for the Super Cab and F150, F250, and F350.
So to answer your question, you may be able to find some nice combinations if you know what to look for, such as in the junkyards. New door panels are extremely overpriced for simple plastic, and you have the after-market kind and the originals. But I guess I would stick to junkyards, or, since you have the Custom, you can paint (durable plastic spary paint is all you need), panel, embroider, or do what you want with the one's you have. You can also get some variations in the headliner too.
As far as the dash goes, you also have the same number of different trim package combinations (above) with the XLT and Lariat offering wood grain for both sides of the dash. Since your "Custom" package is one of the "economy" packages, your cab is pretty plain compared to the other packages.
Also, the exterior trim works in the same manner, based on the trim "package." And this is also extremely overpriced stuff. Snoop around a lot before deciding to pay big bucks for trim.