An EV Converted/engine swapped classic isn't a classic and you know it
Before the EVangelists (see what I did there?) attack me in the comments, let me explain...
The main argument for EV conversions is that they keep classic cars on the road. No they don't, they just paint over another car. Unless you're talking about F1 cars which are heavily influenced by aero, what makes a classic car classic is the powertrain. If you were to stick a brand new Ricardo V8 with the latest snazzy dual clutch gearbox in a Lamborghini Countach, would it drive like a Lamborghini Countach? No, it would drive like a Mclaren 570S. The same goes for EVs. You aren't giving an old car a new lease of life. You are stripping it of it's old life and then using it's skin to disguise it's sworn enemy. Even if the car is given a different old battery pack or engine, it won't drive like it should.
And before you come at me with the same predictable argument in the comments, whether you are making it "better" or not is besides the point. If you have to make a car that much "better", you've quite evidently got the wrong car. If you must have a car look like a certain way, put a replica bodyshell around your battery pack or whatever you're using. You'll get exactly the same experience and don't retalliate with stuff about the "experience" or anything like that because if you're going to ruin a car like that no one really cares how it's been done. It's not like these companies make any real profit anyway.
A final point: if you can't be asked to own a classic, don't own a classic. If you don't want to put up with their various pitfalls, then just don't buy one. It's that simple.