I'm not really up on my KTMs, but seems like that one might be over 10 years old? If so you don't need a certificate of conformity, and you can leave that part of it blank and it makes the form a whole lot easier. I brought a bike in from Australia so went through all this - I found this site to be handy:https://www.spannerrash.com/how-to-fill-in-a-v55-form/
There was a lot of the form that I didn't fill in, yet it was accepted without issue. You don't need numbers for emissions etc. I got insurance based on the VIN with the understanding that I'd provide the insurance company with the number plate once it was registered. I then rode it to the MOT station - you can drive an unregistered vehicle if you're going to a pre-booked MOT and have appropriate insurance. I did the MOT before the registration, again, it can be done on the VIN.
I can't remember now if I had to get the MOT first or not, but I'm 99% sure I did on the bike and on the car I brought in, then once the V5s came through I was straight off to get plates made up and I was on the road. It's a good feeling when you get there!