Definitely keep the Venom if nothing else. Even if it's only a little bit 'Venomed', it's still a HW77 which is a lovely rifle. Most of the others are quite well regarded as well I believe. Might be worth it to just take your time and restore them all to keep?

There used to be a shop in Mill End called Country Pursuits, but the owner was an old boy and decided to retire a few years back.