Pandemonium Records was started about early summer 1975 at 6 Lapwing Lane by Chris Walters and Simon Waldock.
Chris had been Social Secretary of Manchester University (Owens) Students Union during his second year of his BSc Geography Hons course (1973-4).
Failing his second year exams (and resits - despite having all my notes to revise from!), he ventured into setting up the business with Simon and the help of another shop owner from Stockport. (Brian Gilbert - BG Records, Stockport).
They opened a further two shops - the one opposite Owens Park and the other at All Saints.
Sadly Chris died in a light aircraft accident on 30th March 1979, together with his predecessor (1972-3) as Social Sec. at Owens (I forget his name) who worked for a record label (Warners?). A few years later Simon sold up.
A number of friends of Simon and Chris used to live above the shop at 6 Lapwing Lane and some helped out running the business. I lived there from Sept '75 to Aug '91. For a few months I worked for BG Records mobile wholesaling before starting doing the same for myself as 'Rival Records'.
I used to visit many of the shops you mention, also covering Gtr Mcr - Bolton, Bury, Rochdale, Oldham, Ashton, Denton as well as visiting some shops in Liverpool and Sheffield once a week each.