Last 2 :
19D : Man - one island (6) : I've got ?T???A
26A : Experts following in public transport (5) : I've got B???S - thinking of BUSES but not sure why - would then make 19D ?T?S?A...
17A : fatted calf, say, present for festive occasion (8,6) : I have ?T???I?G, ???L?R
18D : the ache that's tormented a noted sprinter (7) : I have ??P?T?H...
got 4 left, all intermingled, unable to break through .... 6D : English doctor exceptionally caring and welcoming : E?B?A???? 16A : Something to drink? Litres one pound : ?????D 20A : Calls one...
4D : "Surmise" : I've got S???E?T, which I think is SUGGEST, which gives me the G for 17A : "Booth" : G?A?L, but I can't think of anything that fits 17A, so I'm wondering if 4D is...