What can we expect to pay?
That's something of a "how long is a piece of string?" question. The rates depend upon type of cover (comprehensive, third party fire & theft, or third party only), the vehicle, where you live, your driving history, and -- to a considerable degree -- the whim of the particular insurer.
Based on being age 40, U.K. license since 1983, no penalty points, full no-claim discount, living in the lowest risk rural area, third party fire & theft cover on a 1987 Ford Bronco II was £166 for the year at last renewal for me.
It really pays to shop around, especially if you are in some sort of "unusual" situation such as not having a U.K. license or driving something which is uncommon here. Many insurers were quoting around £300 to £400 for me on the above details, and some as high as £600.