From
http://www.wolfbane.com/ukdtt.htm:
The Belmont digital UHF channels are 30, 48, 57, 60, 66 and 68.
The Waltham digital UHF channels are 23, 26, 33, 42, 45 and 49.
From
http://www.wolfbane.com/uktv.htm:
The Belmont analogue UHF channels are 22, 25, 28, 32 and 56.
The Waltham analogue UHF channels are 35, 54, 58, 61 and 64.
So there should not be any direct interference. However, as a lot of these are on adjacent channels they may be some overlap that could cause interference. Also, you will need to find out what channels your VCR, STB, etc. are outputting on.