I've never come across an MK clock connector which uses anything but BS646 fuses before.
For our non-U.K. members we'd better explain. The BS1362 fuse as pictured here is the standard 1" long by 1/4" diameter fuse as used in our standard 13A plugs. The BS646 fuse is a similar ceramic-bodied fuse, but shorter and smaller diameter, available in ratings up to 5A maximum.