Very grateful for all help with these clues please.
1ac: “As quick as a parasitologist is keeping wicket? (2,3,5).”
6dn: “Time of depression, maybe, in eastern UK town (9).”
27ac: “Barer of glad tidings (using central Post Office)? (10).”
1a In two ticks - 'into ticks' (keeping) 'w(icket)'
6d Coleraine - 'col (depression) era in e(astern)'
27a Stripogram - spelled with central 'P(ost) O(ffice)'