Can anyone recommend someone in the Spalding area for this work?
No, but you are only a 7 hours return drive or so from Gareth to Mx5 Restore in Westham who anyone on the forum would recommend.
Total of around 26 hrs round trips mind…
CBS at Nelson are nearer than that
The one tip I will give you (learnt the hard way)
You MUST get a photographic record of the work as it progresses, so you know the work behind the wing has been done.
I have a much different photographic record due to the work looking OK on the outside, but not being dine where it can’t be seen
Second that, though it might be tough getting a welder to remember to take photographs (last time, they did some on their mobile phone for me, but then got stuck getting the photos off the phone. I’m not paying them to be photographers though to be honest. Any body shop will stand by their work). Tip; if you take off the seatbelt trim, you can reach in and feel around metal, including the outer panel, and the end of the sill. If they leave rusty metal in their, you’ll be able to feel the crumbly surface.
I don’t have slender fingers, but I can reach back, and feel the outer wing through that rear most hole, as well as the end by the wheel well. Hence I know that I have a S-Special drivers sill that looks ok from the outside, but which doesn’t have long (hoping pumping in some rust converter followed by a mix of waxoyl/engine oil will stave off a repair for a few more months, but also, I am pretty sure the inner webbing is fine).
Probably too far from you, but I have just dropped off my S-Limited at MNS in Nuneaton. I used them for the S-Special in 2009 (respray and 1 sill repair). This time, the S-Limited will need a sill doing (pin hole appeared), and new arch (strangely, the inner wing rusted through before the outer wing, but the lip is rustfree). All necessary work will be covered in the £1200 quote for te respray (car has hail damage, I’ve taken the time to strip back the sills and suspect areas).