As I recall at least from the 1980s onwards full restaurant car services were only generally available on Mondays to Fridays. I would guess that this was at least partly because by this time Open First coaches, rather than purpose-built restaurant cars, were normally used for the service of meals, and on many InterCity trains, at least on the routes to and from London, the same coach that was used as a restaurant car on weekdays was used as designated "Weekend First" accommodation for Second/Standard Class ticket holders on payment of a supplement.
Can anyone remember when the last weekend trains with a full restaurant car service ran, and which trains these were?
Even in the privatised era, until recently there was at least one early morning Sheffield-St Pancras train on Saturdays with a full at-seat breakfast service for First Class passengers. That was certainly the case under Midland Mainline and at least in the early days of East Midlands Trains. I'm not aware of any weekend trains with a full lunch or dinner service having operated at least since the 1980s, though.
Can anyone remember when the last weekend trains with a full restaurant car service ran, and which trains these were?
Even in the privatised era, until recently there was at least one early morning Sheffield-St Pancras train on Saturdays with a full at-seat breakfast service for First Class passengers. That was certainly the case under Midland Mainline and at least in the early days of East Midlands Trains. I'm not aware of any weekend trains with a full lunch or dinner service having operated at least since the 1980s, though.