Lister D Flywheel Removal

Morning all
I have hit a bit of a wall with the restoration of my Lister which has been ongoing, on and off, for 4 years!
I hope the picture is self explanatory but my assumptions are as follows:
1. The flywheel and pulley were manufactured and assembled separately.
2. As such they should be able to be parted again though it appears they have been united since 1943.
3. Once the pulley is removed some sort of key will be revealed which locks the flywheel in place and the removal of which will allow the flywheel to be removed.

I would be very grateful for confirmation that my assumptions are correct or, alternatively, to be put straight so that I can move forwards.
I would also really appreciate any suggestions on my next course of action.
The attached picture shows my current line of thinking and that I have already removed the key which, I think, only secures the pulley.
I have a large set of pullers with which I have attempted to remove the whole flywheel/pulley assembly in one but as I assume there is a separate key just securing the flywheel I have not overdone this. I have not applied any heat as I am not sure where to do this to best effect on such a large mass and am nervous of the potential effects.
I have discussed this problem with various enthusiasts at shows, which gives an idea of how long I have been stalled at this stage, but am not confident I know enough to keep going without some proper guidance.
As such any help which any of you can offer would be greatly appreciated.
Thanks and best wishes.
Andy

Apologies for the duplication of images.
I am worse at this sort of thing than I am at removing flywheels!
Sorry.

No worries - duplicate posts are not unusual. Just click Edit and delete one link.

Thanks. Almost ended up deleting both but seem to have got it right now.

Your 3 assumptions are correct.
Start by removing the burrs on the crankshaft in front of the pulley. Then lubricate the pulley/crankshaft interface both at the key end and down the bolt hole. Go and have a cup of tea while the lubricant soaks in, and then try to use your pullers on the pulley only.
Once the pulley is removed you will reveal the gib head key holding the flywheel on.

Hi
Thanks for confirming my assumptions and suggesting a way forwards. I will certainly clean up the burrs on the crankshaft and will apply more PlusGas. Plenty has gone where you suggest already.
As far as the pullers are concerned there is nowhere on the pulley to get a grip. There is no gap between pulley and flywheel other than the one I have created with the hacksaw blade. Am I likely to damage anything by trying to part the pulley and flywheel in this way? Even if I do create a clearance between the two it will certainly not provide space to install any pullers so I reckoned I would try to gently lever them apart.
Thanks.
Andy