A 'Back-to-Wall' pan needs a 'top-fix' toilet seat. eg there is no access to the underside of the rim to tighten a wing nut, so you get a sort of wall-plug type fixing that screws in from the top, into a plastic sleeve. This is making it hard to identify a solid wood seat for my new bathroom that I can order online, the stock in local retailers being very limited and mainly plastic.
You can buy the fixing bolts on their own:
formatting link
some products have the word 'Universal' in the description. Does that mean I can adapt a regular bolt-through hinge to top only access??Tim W