Wanted - .25 over middle ring XS1, XS2, TX

[XS1UK4digitvin]

Hi, Continuing the rebuild on my 1970 XS1 in cold and wet England, and discovered that the middle ring in my NOS box (1st oversize, .25 over and carrying the right part number 256-11610-10) is the wrong profile and also 1.2mm thick. Should be 1.5mm and have a step on it. All the other rings are ok, and also the other NOS set I have are correct.
Has anyone got a middle ring they would post to me for a reasonable price, given that I am too mean to buy a full set!!

Thanks
Regards