Thank you to everyone who has taken the time to reply to this thread, and also those who have emailed me privately - this is exactly what makes the Hubb such a great resource and I have nothing but praise for Susan and Grant and also those who help make it work. Top people!
As promised, here is the final outcome of considerable efforts made to be able to get back on the road - legally - and I hope that it's of help to others on the road or those soon to be.
I was fortunate enough yesterday to be put in touch with Chris at unchained tours who gave me details of a couple of companies who do quote. I have copied their details below and they are well worth checking out. Chris was a great help and clearly has a lot of knowledge and has himself had similar insurance difficulties.
www.segurogringo.com
www.motorcycleexpress.com
So, how have I resolved my no insurance issue? Well the suggestion came from the ever excellent Cheryl at Fernet who suggested that I 'try' to go direct to progressive and obtain a quote online. I must confess to have not held much hope in regards to this, but thought, despite not really ever wishing to give them any more of my money, I would at least try.
As my infrequent posts on the Hubb probably demonstrate, I'm not one for too much computer time, but did set up a new Progressive customer account so that everything could be received by email and had a go using
www.progressive.com
When answering all questions, I did so accurately and honestly and even mentioned that I had previously had an insurance policy that was cancelled but I wasn't sure (and still aren't) when this was? I did however use a different mailing address (Pennsylvania) but now that I am registered for online use as a direct customer rather than going through Fernets (and having previously used a traditional mailing address in San Diego) it shouldn't receive any post.
The states insurance runs on Vin (frame) numbers and not on registration numbers as per V5 documents in the UK. These American title documents change when registering your vehicle in different states but each state has different rules which clearly shouldn't concern anybody just travelling through.
So, I entered all my personal information and the dreaded non compliant Vin number and was immediately rejected. I then played around with the letters and numbers and as per their website information substituted 0's for o's (No Two Ronnies humour please) and after about 5 or 6 attempts I was provided with a quote.
108 USD for Third party cover including breakdown - you couldn't make it up! It was easiest to use Paypal to pay the amount in full and before the screen changed its mind I was up and running.
My new policy is now very much valid and I am once again able to carry on with my trip.
This has been an interesting little period and I will add to this post if anything happens to my 'new' policy but suffice to say I have had no response whatsoever from Progressive in respect of questions I asked about my original policy.
Hopefully this information will be of benefit to others.
Simon