Nice one! Although not sure about the cheating bit - a garden has to be pretty defined if you're going to call it garden birding/a garden list whatever....
Anyway, not really trying to pinpoint your location, but wondered if you were down Penselwood way at first, (3 counties meeting), but then you seem to be reasonably-ish close to Glastonbury so maybe not....
Had a couple of birds on my garden list when we lived in Wincanton which don't think you've got yet- Firecrest and Lesser Spotted Woodpecker. And they were proper, in the garden, which measured about 10 by 12 metres! Woodcock through the garden one evening, also had a Honey Buzzard fly low over and directly overhead once, which was fairly gobsmacking. On the other hand, not sure if our list was that high - I think I got up to 80 or 90 or so within a 2 mile radius of the house... that'll probably take you about another 3 weeks at the rate you're going??