Hello ClaphamMama,
I used to manage a small shop in Crouch End that specialises in Victorian tiles. I have no affiliation with them and haven't worked there for a year now so this is a genuine, independent recommendation. My reply is motivated by the fact that during my time working there, and now still, Victorian tiling made it onto my radar in a big way. As I walk around Battersea now, I can't help but notice all the damaged paths in front of people's houses or houses that have just put concrete down instead of repairing the Victorian tiles. It can be expensive to fix but if you can at all afford it, is definitely worth the investment.
One of the things that I learned whilst working at the shop was that Victorian tiling is a very specific skill. The tiles are laid by eye without the use of spacers (as you would see with kitchen or bathroom tiling). Often times, you can find a builder or tiler who says that he can lay Victorian tiles but I would insist on seeing examples of any work done previously. The shop is called Original Features and they have a website. If you ring them, they can answer any queries you might have or offer you a referral to a tiler who can come round to give you an estimate. The majority of the tilers work in North London but when I worked there, some were willing to travel.
Hope you get it sorted.