OK. After all the fretting about getting my front sprocket off and the tales of other peoples troubles plus predictions of how difficult it would be without having a chain attached, I went out and spent money on a 2 foot long breaker bar and a 32mm deep socket.
I put the bike in first gear and the thing came off with no bother! No need for wrapping a chain on or wood through the rear wheel, it came off with 1 good tug while in 1st gear.
It's not in terrible condition, maybe some slight curling at the tips, I figure with a replacement being the fraction of the cost of the chain I may as well do them both.
Hopefully my chain riveter will turn up on Monday and I can finish the job up.
Here's the replacement sprocket that arrived.
