Probably sounds a bit crazy but I was wondering if anyone has ever converted a chopped off roof convertible Beetle (not a Cabrio) back to original roofed car.

I seems to me there a quite a few non original convertibles out there for sale and generally they are cheaper than original cars. So why not get a roof from a donor car and re weld it, therefore return a chopped convertible back to original.

Yep you would have to be a good welder and a bit fiddly, has anyone done this?

It's really massively not worth the hassle. In order to do so you would have to get a good donor roof off another car, hence it is almost always cheaper and easier to simply fix up your donor car. If you wanted to do a different style of roof like a Carson top or something like that, then that could be quite cool though.

As above.
The way most of them have the floor pan bracing and rollbars welded in you would have to hack it to bits first.

Just let them die gracefully in the scrapyards donating bits to keep other bugs alive.
The body loses too much integrity once the roof is cut off and no amount of bracing underneath ever stops 100% of the flex.

nearly all convertables have bad rust issues once you turn them into a mobile bathtub and small fatigue cracks in the panels and joints

I'd think about it if I came across an oval choptop but I've only ever seen one thankfully

I used to have a convertible Baja.

Especially in the rain I considered fitting an original roof as a removable hard top, but never got beyond the thinking about it stage.

To make it work I would have had to change the doors back to having the full window frame, But with the existing roll cage it probably would not have been worth the trouble.