It's worth whatever someone will pay, I've been offered £3k for my 28se.

You want to get an agreed value policy really, possibly with some sort of classic insurance company.

But if you've told them what it's worth and it is worth that then that's what you should get, it's going to cost you that to replace it and if you can't replace it with what you get why bother insuring the item for fire or theft?

I've never seen what I'd call a nice Rothmans 28SP in the UK full stop, I've seen some tat at way over £4k though, so you're looking at the cost of importing something like this and getting it on the road in the UK.

I'd write to them saying you're concerned at their doubt of it's value and what you would get for it if it were stolen and how easily they'd write it off if it were damaged.
Tell them it's a limited run of 1000 bikes, send them some photos and tell them if you lost it you're probably going to have to import another to replace it like for like, point out that the "normal" version of this bike right now is £4.5k in a dealer (Fastline).
Tell them a rough Rothmans SP fetched over £4k on eBay, send them hard copies of the advert above and maybe this link, tell them that's 1/2 a non limited edition model of the same bike that doens't even run or have any bodywork.

Keep hard copies of all this and if there is a claim and they make a dumb offer dispute it, after all, you are correct, the market value of an Rothmans MC28sp in the UK is around £5k. That's what you've told them, that's what you've paid for and that's what you want.
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