Welcome to the forum. I'm right over the bridge in Pinellas, not to far from you. First of all, my condolences. 300K for a restoration is outrageous to me, you can get a decent '58 Brougham for under $100K. My question is, what is wrong with it now that you find it is not reliable to drive? I see some issue areas in the paint, I believe a repaint is around 10K-20K unless you can find someone who can just fix the problem areas. If you repaint, you might want to find a used trunk/deck lid to swap out with so you don't have all that rust, I'd guess the lettering or the stainless trim is letting water in and it sat, rusting it out. Other than that it looks to be in good shape, does it run well? What about the brakes (you might want to have the original system swapped out for a newer brake booster/dual master cylinder and disc brakes up front)?
Jose welcome aboard. Sorry to hear about your father. I agree with Dan's comments. I would be looking to maintain it, with perhaps addressing some of the problem paint areas. Love the car basically as is. By maintaining it you will have more of a connection with the car to your Father, as that is how it was when he owned and drove it. Just keep it safe and operational. As Dan said, perhaps address some paint issues and perhaps the trunk lid. $300,000.00 for a restoration is nuts, even if it needed a complete one which it does not appear to require. Clay/Lexi