So I recently got myself two of the engines used in the iconic train scene.  I can quote the entire scene line for line, it's one of my favorites, and I was going to build a diorama, but I came across this signature and thought it'd be a fantastic way to make a shadow box instead.  Unfortunately, I have some concerns.  First of which is the "Gomez" signature, which the seller denotes he's "never seen on any other piece".  I haven't found it on any others either.  When I contacted him about a COA of any kind, he said he got it himself and I should take his word at it.  I know all too well how this market is flooded with fakes.  He also mentioned his reputation was spotless but when I checked here, it seems like he's a mixed bag (Also goes by JJ Buttons or Spyrograph on ebay, if I have my info straight).  But, he's had legitimate stuff.

I desperately want this to be the real thing but don't want to get burned by it.  This area of collecting is outside my normal expertise and I know I'm not the smartest person in the room here.  Can anyone give me any insight here?  Thank you!

https://www.regisautographs.com/product/raul-julia/