That takes me back!
Before the Low Flying System was revised at the end of the 1970s, the main LFAs were much smaller and most were interconnected by narrow 'link routes'.
To fly from Wittering to Wales and back, all at low-level, you set off on a link route down towards the south west and entered LFA 4 (?) then routed through there to another link route to the Welsh LFAs (7 and 10?). Many people drew up a standard route from Wittering to Wales; originally there were (I think) 2 link routes to Wales but another one was added later which went near pork chop lake.
The route was nicknamed the 'Ho-Chi-Minh trail'; so a typical LL task would be "4-ship, Ho-Chi-Minh north, targets here, here, and here, reverse Ho-Chi-Minh south, standard break" or similar.
Unfortunately I lost my old 58 Sqn Ho-Chi-Minh map years ago, so please excuse any inaccuracies brought on by senior moments!