I started at MGS in 1955 after passing the 11-plus and was there until 1960. I left to join the RAF, but before that worked with my Dad for about 3 months at Harris & Sheldons in town. I was in the same Form as Chris Spedding (ex Roxy Music, & "Motorbiking")and Keith? Pritchard, who I believe has now passed away, from The Fortunes. Also, Jasper Carrott was there at the same time but a year or so below me, and therefore a "fag" and not worthy of consideration!
As far as Cheddar Rd being "posh" is concerned - we had the usual tin bath hanging on the wall next to the one and only outside toilet, by the "coal hole", and the mangle, and the wash tub + dolly. However, we were better off than my Gran, who lived in George Street, and had to share her outside Loo with two other households! so maybe we were a bit up-market compared to others! We also had electric light, although next door, No 8, had gas lighting until the 1950's (Cissy West was the name of the old lady who lived there). I can still remember the "pop....pshhhhh" sound when she turned the lights on!