The old MMM Vol 2 says for bars 25-40:  
25-32: 1st and 3rd couples make a circle and dance 8 slip steps round to left and 8 back again.  
33-40: 1st and 2nd couples make a circle and dance 8 slip steps round to left and 8 back again.

The revised combined MMM edition 0f 2007 says:  
25 - 32 1st and 3rd couples dance four hands round and back.  
33 - 40 2nd and 1st couples dance rights and lefts.  
(this is the same as in Miss Milligan's still earlier "99 More").

The source is given as:  
Skillern, T: *Twenty Four Country Dances for the Year 1781*  
Customary tune: *What you please* (Skillern)