Unusually, a fairly complete set, one 20 and three 10 line intercoms (plus one for parts). Condition is used and functionality unknown - from an estate clearance where several of these phone/intercoms were and some are still installed.
https://www.ebay.co.uk/itm/Vintage-telephones-The-Reliance-Telephone-Company-20-and-10-line-intercom/163890985982 ( dead link 04-13-21 )
These were very popular with British department stores and small businesses as a supplement to the PMBX switchboard.
Edit: Bidding closed at £17.69 + P&P which must be a bargain for 4 complete intercoms.