I think the z50 boot will work, They might be tight to fit on to the bottom but should be close enough to look decent. I have an Auranthetic electric minibike which uses the same Taiwan made forks as the fox pics that JPR posted, I have a z50 here as well, I'll post ups some comparison pics for you this evening after work.
there was a set of boots that looked like they would work that just ended on ebay, I was watching them and forgot to bid. I would have been outbid, they went for almost $40. Supposedly the early Gemini 2 stroke bike had these forks as well (auranthetic used Gemini supplier to make their bikes) the guy that has all the Gemini parts in CA does have one set of NOS boots I am told that is holding onto them maybe to make repops off of someday.