Pascal Did you spray lube into the adjuster at the back bottom of the drum. Then with a brake tool or flathead srewdriver turn the tumbler, so the shoes come in. Maybe take the drum and wheel off at the same time.
I forgot to mention I got the wheel off within 18 hours with a bumper jack and a 2 x 4 behind the rearend against the other wheel/backing plate and a constant pressure... it fell off the next morning when I went to ad some pressure cranking the jack some more, It was a farmer who told me about this idea.
Congratulations! it acutally looks like it came off clean, I thought maybe some of the cast iron from the brake drum would be stuck to the steel wheel.