crete you're not correct there.....many shops in small towns etc across Scotland still take a half day Wednesday...all the towns near me do (and I live just outside Edinburgh). You'll find the chains etc (Boots, Tesco etc) don't, but the small independently run shops still take the half day.
Small towns may have some shops that have a half-day. This isn't always a Wednesday, but can be a Tuesday or a Thursday. In the case of Thurso, they also close for a full day on the first Monday of each month in summer!