Fun cars to drive indeed, I have one with some wear but was well kept and its still fantastic to drive.
But mine is the European version so all you US guys with the cheap gas are missing out quite a lot when it comes to 924s.
Originality counts for the people who care about it(and those are the only people who will pay serious money for your 924)...but that nose panel has to be restored...you cant expect damaged paint to be valued more than restored.
That being said my advice is to do the minimum required restorations and NOT go all in.
So if I were you I would just repaint the nose panel, front bumper and the headlight covers...give the rest a buff and be done with the paint job restoration.
Do pay for a professional color matching and paint job though, anything less than factory quality will lower the value of course.
That's great interior, very 928 like. Make an effort to fit the carpet under the door sill and look for fixable details like these before putting it up for sale.
Fuchs look good on a 931 but you have to lower it.
To be honest the factory wheels are the best for the standard ride height and tires.
I would just leave it as it is as it looks good and original...and if anybody is to pay good money for your 931 its only going to be because its in good condition and all original.
Try to get a set of correct mats, these were optional when the cars were new as far as I know.
Get the correct plug leads don't leave the el cheapo blue ones there, paint the air filter box black and replace the turn signal on the passenger front corner.
This car is for sale at $49000 and I think it will sell close to that.