The Electabuzz linked above is owned by @swolepoke
If you grab it I will be able to stop thinking about buying it…!!
I have purchased a Sugimori signed card from him recently. He responds quickly to private messages here, ships fast, and is happy to share provenance info.
Tried working out a deal with OP back in May with no luck :’)
As stated previously, the signed Electabuzz card is my listing if you’d like to work something out. Other than that, all other Sugimoris I own are in the personal collection.
It’s always tough to be 100% conclusive either way because of the inherent variability in signatures. It can also be hard to explain the subtle details that makes an auto “feel” off. Knowing the Japanese characters well is very helpful because the forgeries are almost exclusively from westerners but even absent that knowledge, the thing that really sticks out to me are the “S” and “R” in that signature.