Yes, it's a good idea - as long as you can rotate the drum relative to the hub a little first. Then the ends of the bolts will push against a flat surface. I didn't do this - just used the tyre levers inserted between the back edge of the drum and the brake backplate, then gently levered it all round until the drum came off. If there's a significant lip on your drums though, you'll struggle doing it this way.
The auto adjusters are sat between the brake shoes, just below the brake cylinder. Shown nicely (though everything's covered in oil, which it shouldn't be) in fiaty's photo in this thread, immediately below the retracting spring:
https://www.fiatforum.com/multipla/319430-leaking-brake-oil-left-rear-wheel.html
Cheers, and thanks for the ultra quick reply!
M.