In East Anglia, names with the structure X-ing-ēġ give modern forms in -gay rather than -gey (with date of first -a- spelling):

Bungay Sf (-ay 1235)

Gamlingay Ca 160 (-ay- 1271)

Hilgay Nf

Shingay Ca 65 (-gaia 1087-93)

Wormegay Nf (-gai DB)

The only other -gay names in England (none certain to be -ing-ēġ) are Bogay Hall in Solihull (?cf. Bog Meadow Wa 347), Harringay or Harringey, Lingay or Lingey Ca 78, 119.

What's going on here?    Was there an early pronunciation in /ai/, caused somehow by the -ing?

Keith