Don't think Hutton would have batted at 3 often enough.I actually thought it was more likely Hutton !
This is very left field, and I wasn't going to include him, but with that clue I'll go with Frank Woolley
Ah Frank Woolley, what a guy. Not the answer, but what a guy. Just had to check how his batting record broke down, he did bat at 3 more often than anywhere else but as he seems to have been the Moeen Ali of his day than isn't saying much. I've read an interview from his last season or two where he's really excited about finally being given the chance to open regularly for Kent, right at the end of a 32 year long first class career.
I'll pop back during my lunch break with the right answer on the off chance anybody else wants a go.