Shooting The Derbyshire Yew

I've had 4 test shots, bearing in mind it's pretty cold and I've not worked up to full fitness I'm only drawing about 28.5" (scaled off the video).
I also didn't warm up... It's only since I reached about 50 that I ever felt the need to warm up, before that I'd dissmissed it as just bull and totally unecessary!
The tiller is looking pretty much as it was before I did the nocks. I'll put it up on the rig and measure the draw weight and length and cast a critical eye over it. Maybe the outer limbs could work a tad more. If I flex the bow I can feel the bend at the grip, but with those relatively heavy arrows there isn't really any hand shock, it's just all a bit of a strain on my elbows, shoulders and fingers. I daresay, by Sunday, with an open field to shoot at I'll be able to do it justice.
The arrows are 767grains, that's heavy compared to my usual target/field arrows but not as heavy as 'standard' Warbow arrows.