Sorry to hear of your collision and I wish you, and the Ariel, a speedy recovery.
As Paul has stated, I would also suggest that you speak to someone who can advise you on what action you can take to recover the FULL monetary amount you are entitled to. In my experience the insurance companies will try and sort it out quickly, write the bike off and offer you some cash (the suggestion that you take it to an Ariel dealer suggests they are not experienced in dealing with classic bike claims). If you take some legal advice from a reputable solicitor experienced in Road Traffic Collisions / personal injuries...usually an initial consultation is free....you may well find that, as it is a classic bike and a treasured personal possession (as opposed to just a mode of transport) you can claim for a rebuild (for the bike) and receive compensation for your injuries, any loss of income, and any other expenses incurred as a result of your injuries. A solicitor will also advise on the possibility that injuries may never fully heal and compensation can be claimed for reduced loss of mobility, however slight. In over 90% of cases the 'other side' will settle out of court, even higher % when their client is clearly in the wrong.
It may seem a lot of trouble, especially if you are feeling unwell at the moment, but investigating your options, and starting the ball rolling early, can pay dividends further down the line.
The 'sneezing' explanation is an old ploy as 'automatism' (total failure of voluntary control) is a defence to careless driving. However, it is rarely successful as a defence as the time element of a sneeze is very short. In a case such as yours the other driver should have seen you for a significant time interval before the collision.
Last point is that, whether or not the Police prosecute, does not affect your ability to claim or the amount you can claim.
All the best, hope you are both back on the road as soon as possible.