Incidentally, I put the Carledo on the road in 2011, years before it became tax exempt or MOT exempt (if it was liable for MOT exemption at all, which is dubious) And i've continued to get it MOT'd every year since. But this means that whenever the tax rolls round for renewal, the car is already MOT'd so I never even get ASKED the question of whether it is exempt or not. It's my firm policy to never give a give a govt agency information that may later be used against me when they, inevitably, move the goalposts! I'd advise anyone in a similar position to do likewise!
I agree with giving minimal information to the government, just stay the right side of the law. I take the opposite policy with insurance, don't want to give them any get out if I need them to payout.
I also can't agree with the person who suggested that a Toledo "ruined" in this fashion is worth the same or less than a similar condition standard car. Available data (which I track closely from obvious interest) from the few completed projects of this type offered for sale (and sold) seems to indicate an approximate value around double or more that of a similar condition standard car! So go for it and good luck! It makes a fun vehicle!
I didn't mention anything about ruined, I just said that you are unlikely to get your money back. A genuine Sprint is worth more than a Dolomite that has been Sprinted, for example. Also you can't base values on asking prices. Ebay is a good place to see this, since you can find out what cars sold for. Many cars have ambitious asking prices but either don't sell or go for far less.
I can understand why that would be the case. I would be willing to buy a car you had modified because based on your contributions here, you know what you are doing. A car modified by someone I didn't know, I would be far more wary. I would have less concern if it was merely an upgrade to similar spec of the same model.
However if it was a modification that involved an engine never used in that car and other non-standard parts, I would be cautious. I would have no idea whether they were a competent welder, for example, so how would I know if modified mountings for components were secure. Then there are issues like weight distribution, have they properly adjusted the suspension to take into account the weight of the new engine? The further from standard spec you take a car, the more skill you need to do it properly.
So I can see why people can be wary of modded cars. You do need a bit of expertise or someone to advise you that has such knowledge, to buy such a vehicle.
I used the word "ruined" in parenthesis and a large dose of irony! People like me are often approached by the "rivet counters" at shows and suchlike to be told "you've ruined that mate!" It's become a standing joke in the modding fraternity, look on Retro Rides forum, there's a whole thread devoted to the subject with many pictures of "ruined" cars!
There are 2 levels of mod involved here, the "all Triumph" lower level proposed by the OP here is a pure bolt in conversion that anyone with a decent toolkit and a bit of savvy can achieve in not much more than a long weekend, then there is the "full Monty" job that nutcases like me indulge in which can take anything from a couple of months to many years to get right! And yes, if you are thinking of buying something in the latter category, a thorough in depth inspection is a good idea as you don't know what bodges have been perpetrated or how fast and loose the builder has played with the 8 point rule (ESPECIALLY THIS!)
But of the few that come on the market (only 3 that I can recall in the last 5 years or so) in running, driving condition, Martin Bellinger's excellent Redtop powered car made £6.5k, 5 or 6 years ago, A green Sprinted 2 door with EFi from an XR3i or similar made £4.2k and needed work to get roadworthy, that was about 4 years back and, most recently, the lovely Honeysuckle Honda S2000 powered 2 door made around £9k in the last year or so. I've turned down £6k for the Carledo in the last year, even though it's now getting tatty from constant use. Because it's a proven and reliable car. (quick too!) A tidy stock 2 door will struggle to make more than a "real world" £3k at todays prices, though i've seen a few optimists asking £5k or more, these cars don't appear to have sold. The relative rarity of the 2 door cars doesn't seem to have impinged on their percieved value, where the modified cars sell on the quality and performance of the mods, the "fun factor" which is a completely different marketplace.
I agree that a Sprinted 1500 or 1850 like yours is worth less than a "proper" Sprint (ie a car with a Sprint logbook) this is fair IMO. Modifying a "real" Sprint as I have done with the Dolomega is probably a bit of a mugs game too. Not that it is ever likely to be sold whilst i'm still breathing, but my guess is that it's value, to the right buyer, would be little, if any, more than a comparable standard Sprint auto, with the "fun factor" merely making up for the value lost in modding a rare Sprint. But in a relatively much smaller martketplace. HOWEVER, that would still be higher than if i'd done the same conversion into a 1500, so, in a way, i'm still ahead!
I'm with you on insurance, declare EVERYTHING and take your lumps, then they CAN'T stiff you if you are unfortunate enough to have a prang!