My mk1 is a 7/73 build, originally a 1300 auto, one owner, with 38,000 miles and still had what appears to be the original 12in steel wheel spare. It's marked Dunlop Guardian 6.20 L12 LP 41, 4 ply rating tubeless. The Tyre ID number is 7Z33462N. From what I can find it was made in China, the last 3 numbers apparently mean it was manufactured in the 46th week of 1972, going by the look of it I doubt that it was any later decade. It also predates my car which should rule out it being a replacement. Although I could be completly wrong A google search shows these being advertised in the late 60's and early 70's. Hope this helps.
Dave.