Yes.
After Smile, Humpy Bong and Morgan he got out of the professional music business and got into model-making. Thomas The Tank Engine is probably his most high-profile job in that field.
Some websites claim that he also built the alien model for Roger Taylor's Fun In Space album, which appears to wrong, given that that sleeve for FIS credits Alistair Bowtell.
He got back into professional music in the '90s, doing clubs, then recorded his Amigo album. I bought the album on the recommendation of a friend and it is quite good, mostly jazz and folk, with a few rock and pop numbers. He and Brian May do a good version of Smile's "Earth" and "Doin' Alright" on the album.
Not calling Tim a liar, but there's no evidence other than his statement.
It's possible he was on the team, but did they need a team to build a little alien model?
Mr. Bowtell passed away in 2006, so the only person we can ask is Mr. Staffell to account for this discrepancy.
For now, I'm siding on the sleeve notes.
FriedChicken wrote: I believe Tim Staffel also mentioned it on his website (his old one) i believe.
Perhaps he was part of a team?
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I was checking out a 2003-2007 version of Tim's old website through a web archive service and didn't find a reference to any Fun in Space work (though there was a fairly detailed narrative on the other graphic/modelling work he did), but I did find a nod to queenzone in his list of thanks for his Amigo project, which was kind of cool. He does speak about some work generically, like "high profile media projects" for example, but he talks about Roger and Brian, so it seems like something he might have mentioned by name if he had a significant role. So not sure, but nothing obvious on the site that I saw. :)