The argument seems to stem around it once being a furniture shop. Was "Dee Discount" a furniture shop? The period of early 80s is about right.
There isn't anything on the Virtual Tour apart from some shots of the back of it in the 1970s.
No, what is now the Boots shop was a branch of Garsides of Glossop, a furniture shop. Icelend was variously Dee Discount and Gateway (interesting that those supermarkets didn't survive. Gateway became a part of Fine Fare, I think, who then became part of Somerfield and we know where they ended up.)
Before the building that is now Iceland the site was occupied by Trinity Methodist Chapel (hence Trinity and Chapel Streets in the vicinity).