Firstly- why the foc was he reversing up a slip road?
If going through the insurance should get police involved as that's obviously a big no no for which he should get done for it and deservedly so!
For the age of the bike the damage will write the bike off, any estimates go on genuine replacement part prices, not forgetting that if you do go through insurance everything will be claimed for and costed- including small scratches to any engine casings, mirrors, indicators, foot rests, levers, etc etc.
You can loosen all the bolts for the front end ( lower and upper yokes at the forks) then re tighten, sometimes a nudge can twist things slightly, loosening and re tightening can put them back to normal.
Yes, your premiums will go up slightly, even when claiming a non fault accident (which yours is) and claiming through the others insurance company! It's an absolute disgrace and 4 non fault claims in 5 years has seen my insurance go up to stupid!
We're you injured in any way or was your helmet/ clothing damaged?
If not I'd be tempted to suggest £500 to the dick that knocked you off, you could get fairing and a (better) front end for that!
The problem with accident solicitors is they're not that interested if there's no injury, that's where the money comes from and since the change in law not many would be bothered to take on your case.
Now the annoying flip side is most insurance companies are not happy to deal with the third party their insured driver has hit directly (in my experiences) and therefore you're pushed into finding a solicitor!
If you do go through solicitors/ his insurance then have a hire bike immediately, even if you're happy to ride yours- they will pay out the value of your bike within a couple of weeks as an interim payment as bike hire charges are astronomical for insurance claims (I had one which was charged at £60 per DAY, they payed out for my bike but I still needed to hire a bike, signed some paper work and the bike I had was charged to me at £80 per WEEK as private hire!)