I'm having trouble making heads or tails of this info. Do you mean; p0301 (#1 cyl. misfire), p0307 (#7 cyl. misfire), p0300 (multiple random misfires). Sounds like something dealing with the coil packs: wiring problem on the coil packs, high tension lead problems, cross firing on the high tension leads (plug wires).

'99 Disco II
'95 R.R.C. Lwb (Gone...)
'76 Series III Hybrid 109
'70 Rover 3500S