Thanks Bonny. Well it's been 3 months since I posted, and since then we've hid the pens really well so he hasn't come in contact with a pen since then. We had a couple of pens out recently to give it a test and he didn't go after them at all, in fact when I was using a pen last night, he was on my knee and didn't even think about going for it. Which is quite amazing considering what we've been through. I guess he needed that break! Although we'll continue to hide the pens anyway, just in case. What a relief though!

Thanks for replying!