Thanks all.
The best guess on LFGSS was for a bottle cage, but you'd think they'd stick the pump on the top tube and the second cage in the usual place.
I suppose the fact it has pump pegs, dates it to before the position of bottle cage bosses became standardised. However, it has top tube cable guides, DTS bosses and an under the BB cable guide, so it can't be that old.
The bosses also seemed quite prominent compared to the usual, but I guess that would be to clear the seat post clamp.
Every day's a school day...