Have you got a photo?I noticed that the roof doesn't sit as far down after fitting the glass screen. It still allows the tonneau to be fitted, though. It has settled further down as time has gone on.
Early Mk1 MGF's had side seams but NOT BAS Sportster Hoods! Late Mk1's, Mk2 & TF's had the later design with extended front corners and dispensed with 'side seams' with a 'one-piece' top section. As can be seen in this MGE article: http://s591.photobucket.com/user/MGFMania/media/MGFManiaP74March2011.jpg.htmlThe only difference in roofs that I am aware of is on early mk1's which have the sporster style hood with 2 seams down the length but I thought they still folded flat.