This is what I wondered mate but wasn't sure I'd I should get a current valuation first. Getting it finished or at least very close before going the agreed valuation route seems the best idea though.
You've certainly got the right idea getting an agreed valuation policy.
I don't know about the US, but UK insurance companies have some very nasty rules that can catch you out.
For example, with just a normal policy, if you bought something like a classic XS650B 25 years ago for £500 in mint condition (which was most definately possible then), and it catches fire next week, you'll only be getting a £500 payout.
This is because their rules state that you cannot make a profit out of a claim.
So if you tell them it cost £500 that's all you're getting.
If however, you sold the bike to your brother 10 years ago for £2000, and then bought it back this year for £5000 because you really missed it, you've got a chance of a decent payout.
Far better to have an agreed value policy but check over the small print really carefully.
It may only be insured against theft if it's parked in your locked garage while at your address.
At someone elses address it's insured parked on the drive at night, but not on your drive at night.
So if you do leave it on the drive and forget about it, and it walks off during the night, force the garage door locks pronto, before reporting it stolen.