Its a long one! short outcome:
On the way to the garden centre i inadvertently caught something in the road thought i had got away with it but no! tyre pressure warning light straight on

made the decision to head for somewhere i knew to be tyre shop's but never made it, so Mercedes assist and RAC roadside( the guy that turned up was a legend) later (small split in side wall) 2 front tyres fitted at just under £400. and to add insult to injury SWMBO spent another £50 at said garden centre.
A sad day but enlightening.
Thanks Tony.