At times like this it pays to be philosopical.
Your explanation as to why it doesn't fit sounds wholly plausible. You've run it up the flag pole, and I, for one, am prepared to salute it. If
you are reconciled to the idea that you might need a major renovation of the windscreen to correct the situation, that A. you're not sure you
can afford, and B you have no idea whether it will correct the problem, then fall back on the notion that you're happy to drive it topless.
The decision is yours, Do you plan to get this up to A1 standard and better? If not, then good solid hardtops can command a respectable price
on Ebay. With the proceeds you can acquire a decent tonneau cover, and have some money spare to lavish on other little features the old banger
is perhaps in need of.
You get hold of some ready's to continue your rolling rennovation, and some other soul gets a first rate hard top which actually fits their
car.