I (my dad) have a lot of Advanced Squad leader stuff at home. I've never played it before, a reason for that is that it seems the rules will take part of a lifetime to learn. But my question is, would it be desirable to play ASL with the new WW2 range coming up? Is it possible to mount them on bases that fit the board and does it work with the rules? If so that would be a reason for me to start learning those rules!

If you stick to the first few chapters of infantry rules they're really no harder than a lot of rules out there. I played a lot of Squad Leader when I was in high school.

I think the real problem will be stacking. How do you put two or three squads and a leader in a single hex? I don't think it would work on the map boards, unless there are versions of the maps with bigger hexes.

It definitely works.  If your dad has https://boardgamegeek.com/boardgame/5292/streets-fire-asl-deluxe-module-1 then you can see how it is done; if not, you could probably work out the methods from the description.

Still the problem extra crispy adressed persists? how would I stack 4 bases? Or is that explained in the rules of the deluxe module?

Yes, it explains.  Basically (IIRC) they re-sized the hexes so that you could fit everything in under normal stacking limits and supplied appropriate map boards to show. 

If I were planning on doing this, I'd have a look at this module then get/make some hex terrain so I could make my own scenarios using the same sizes. 

Bigger hexes is the answer. These guys seem to be playing with 4" hexes, I think. I've seen some Stalingrad scenarios done in 15mm with 4" hexes and it looks pretty good.

I wonder what the plastic 20mm figures are? Clearly markers of some sort. Still, not a bad looking game...

They are sniper markers. You can just make out the American sniper counter on the base of the one in the foreground. These guys seem to be stacking the counters on the bases with the figures. That is probably a bit less effort than the alternative I saw where the 15mm guys made sets of figures with the factors painted on the back of the base, so you needed one for each type of squad and half squad in the scenario.

BTW, I picked up this photo from the Facebook ASL group. If you scroll through the photos you can see more shots of the game: https://www.facebook.com/groups/advancedsquadleader/photos/

Why go to all the bother? Use the counters to play the game and select one of the huge range of rules for figures to use with your miniatures...

I've moved onto Lock n Load for squad level board gaming from Squad Leader I could never fathom the great volumes of rules ASL had...

:-)

I plan on using Blitzkreig Commander (aka BKC) with the Baccus WW2 figures ... assuming I ever finish my mountain of Sumerian 6mm figures!

Figure game rules for games with figures seems sensible to me :-)