Cant really see but it could be an old crabtree. It's old whatever it is. If I am right and if you can still get them you will be looking at an electrical wholesalers or eBay.
going by questions 1 & 2 I would say do yourself a favour & get someone in.I'm all for folk doing the basics but faffing about with circiuts & consumer units I wouldn't encourage.seen too many horror stories & lucky escapes.not what you want to hear but trust me I'm doing you a favour.