I'm reminded of an older gentleman who owned a Spitfire (aeroplane, not car). He announced one day that he was going to paint it pink. You should have heard the abuse the poor guy received.
His parting shot was something like "It's my b
y aeroplane!! When you have your own Spitfire, you can paint it any f
ing colour you want!!"
Or words to that effect.
I have what was once a Yellow Ochre GTJ (1969). When I bought it, it was a metallic burgundy. It is now going through a full resto, and will come out painted French Blue, with a 1750 Mk1 Zagato interior (it came with it) and a 1600 engine (came with that too). I'm going with a dual master cylinder unboosted brake system with a balance bar for proportion control, and Willwood hanging pedals (instead of standing pedals). Electrics are being totally redone, and all fuses and relays will be in a drop down panel under the glovebox.
My brief to the guy doing my car was that I wanted it to be a sleeper. From the outside, I want it to look like a stock GTJ, except for the Momo Vegas. On the inside, and under the shell, I want it modernised where possible to take advantage of improvements made over the last 40 odd years, to improve reliability and driveability.
I must admit that the only body panels I'm keeping are the firewall/engine bay, and the roof. Everything else was rotten/damaged beyond all recognition, but in the end it is your car, do with it what YOU want.
The question of originality can be taken to the N th degree. How many people are running cross ply tyres? How many used the original type of wiring when they re-wired their car, with the original wire markings and wax string? Originality is all a matter of perception. I'd rather have a car that I enjoy, and grow old with, and hopefully that is what I will have after my car is finished.
Do what YOU think is best for YOUR car, afterall, you are the only person who has to live with the decisions you make about how you restore it.
Think about what you want to get out of the car. Concours, competition, daily driver? Original Concours cars are usually trailered to competitions. Me, I believe cars are for driving, hard. So that affects what I do to my car.
Have a look at other Alfas around you. See what they have done. See what you like and don't like. Heck, many Alfas were modified on the production line before they were finished because they ran out of one part or another. Do you rebuild it how it was supposed to be, or how it really was??
It's all up to you. No matter what you decide, some will like what you do, others won't. That is just how it is
If you want to modify and be accepted, come join us on the Darkside at Scuderia Non Originale
But be warned, nobody there will tell you what not to do!!
Just my 2 cents. Enjoy your car, whatever you decide. Afterall, you bought it to enjoy it!!