Now if only Mott The Hoople by Willard Manus - the book they named themselves after- would get some respect. That book's great and has been completely overshadowed by the band.
I loved Mott, they were on of my favorite bands when I was a 16. One thing, though, Stan Tippens also played keyboards with them, and my idol Ian Hunter mostly played guitar.
@3 Tippens did play some keys, but he fronted the pre MtH group, the Doc Thomas Group, and Hunter was not hired to play guitar, but to take Tippens place. That was in the run up to the first LP. What shook out later was exactly as you say...Tippens playing keys some and Hunter playing guitar.
Street Corner Boogie was part of the soundtrack of my wayward youth...