I'm posting this here rather than the classifieds because I desire to help out my fellow late '70s Sovereign
owners, and perhaps build some pay-it-forward credit for any spare parts that may materialize.
I have a set of four 15" black steel wheels and tires sitting around gathering dust. I upgraded to 16" alloys and LT tires last year, and the old ones are just taking up space. They have 50% tread life remaining, and make excellent spares, which is what I've been using one of them for.
I live in the Chicagoland area if anyone just wanted to swing by, if you wanted to take up to three of them. We could negotiate a deal for the 4th one, as that is my spare. But I wouldn't mind upgrading my spare to match the other 16" tires on my rig.