My Figaro came here with 12 year old Japanese tires and no spare. The set was hard and old and needed replacement. The factory size was not to be found in the US; importing from the UK would have been $$$ freight. But Walmart has listed
Americus Touring Plus All-Season Tire - 155/80R12 77T for $49 each. Drop shipped to a store in town here at no charge. These are Chinese made, as are the UK ones I saw listed. Install was about $30 each including road hazard coverage. I'd like to report that I am quite satisfied with them, install, ride and handling. I don't know about the life expectancy yet!
Ebay had a half dozen factory spare wheels for the car, all in the UK. I ordered one up, but Ebay's Global Shipping program impounded it when it got to their center, claiming US customs was at fault. Really?! Then they took down the other ads for them. Oh well. I found none in the US, nor any road wheels. Solution? Several stores locally had trailer wheels complete with 4.8x12 tires for around $75. They are 12 inch rims, by 4 inches across the stud holes, and fit just fine. They are much like any space saver, and don't want to go too far, but will get you home if needed. And it fits fine in the trunk [yes, boot to you over there].