Do not worry about the valve recession problem until more study is made.
Actually, there is a thinner shim as shown below that would get you another .001" + a scoch. see below.
You should probably make some actual measurements of what you actually have now so that more help can be offered.
Generally if 1 is too tight it will be an exh. I just tore down an 85 engine that had 378,200Km. 1 valve was too tight and it was adjustable. Another valve was so deteriorated it was barely there, but it was still in adjustable range.
A couple of possible solutions: Kawasaki makes similar valve shims that are said to be the same diameter. I do not know if any of them are thinner than 2.0mm????
As a last resort, you can take some of your used shims to a machine shop and have them grind them thinner to your spec on a magnetic table grinder.
I think you need to go back and look again and be sure this is correct as you've seen it. If it is so, I think it's unusual.
Did this engine run? if so, how well. Tell us more, please tell us what clearances you have on which valves.
11 32 1 460 147 | SPACER - 2,00MM | 0.02 | 8 | $6.19 |