question on ground schools near Aylesbury UK/"Grope Trainer"

Okay so i have yet 2 other questions that i am trying to figure out after having visited East Anglia last week.  My uncle talks about going to "Cheddingham" on August 19th and visits the Red Lion pub in Aylesbury.  He also talks about it being filled with RAF's. 
When i was over there last week, i visited 2 Red Lion pubs-1 in Aylesbury and 1 in Wendover near an RAF base-both are about 6 miles from each other and each have a canal near them (he mentions walking home by way of the canal).  When i spoke with an elderly employee who has been at the wendover pub for 70 years she said that during the war the pub would have had 3 locations, filled with RAF's and uniforms because of the base-what i cannot reconcile is this:  was there a ground school in a place called Cheddington or was it Cheddingham that was run by RAF instructors (he says both) and if so was it closer to Aylesbury or Wendover (a suburb of Aylesbury).  Both pubs have been around forever as well.  After his time in Cheddington (ham) he went to Bovington for more schooling before returning to Wendling on August 28th...thoughts?  I think he is talking about the pub in Wendover due to its location and proximity to the RAF base but he refers to the Red Lion in Aylesbury...
The other question is this: he says: "After supper went to the briefing on the "Grope" trainer-worked out a flight plan.  During the briefing the 17's were returning from a raid-counted 81-impressive formation."  I cannot read his writing on the word before trainer but it looks like a G_o_pe...any help would be greatly appreciated!