They sound lovely Kaz
Our sofas are dark brown, we got them the Autumn after we moved here; they were half price but still expensive - but looking at them now, you'd think 2-3 years old at the most
I know people do let their dogs on furniture, but one of the best tips I ever heard at dog training was 'imagine your dog is 'this' size, and that's how you should always apply rules'. Whether that's jumping up at visitors, pulling on the lead, or taking over the furniture, it's a good way of thinking.
They're dogs, and should be treated as dogs. Much-loved yes, part of the family yes, but animals, not people.
I've only ever had big dogs so it's maybe easier (although of course they started out as small puppies), but people with bigger dogs than ours still do it - I never have.