How to put Car back on the road after an accident

[Austria29]

Hi

Does anyone have any knowledge of the rules regarding getting a car back on the road after an accident

I have looked at a few websites but it is still not totally clear to me

I was involved in an incident recently where a builders truck ran into the back of my 1990 740 estate while I was stationary

The damage was such that the car was written off and the car marked as Cat S. Damage is to the frame as the rear doors no longer open and the spare wheel well is pushed in so it will need to be pulled out

I have managed to buy the car back and am going to try and get it fixed as I only recently acquired the car from of a friend of my dads who had bought the car after it was one year old and had kept it ever since. It has only done 100K from new and has a full history with no expense spared in looking after it

If the repair is successful - what do I need to do ?

I still have the original V5 in my name from I bought the car - Do I need a new one which I presume will show the Insurance listing ? How do I get the new V5?

Do I need to get a new MOT?

The car is still insured although currently declared SORN - Is that policy still valid or do I need a new one as I read that Cat S cars are more expensive to insure

All advice and comments very welcome

Thanks