Classic Modules today.
My longtime fascination with Mystara has naturally brought my attention to several modules set in that milieu, which are:
B2: Keep on the Borderlands
B3: Palace of the Silver Princess
X2: Chateau d'Amberville (Castle Amber)
Naturally, you still need the original modules. But you can find those online at DriveThruRPG as well at www.dmsguild.com.
I really wish that all the classic Mystara adventures could be converted -- but for me, that's just compleatist talk.
I'm looking at maybe creating some output as well for the 5th Edition rules, but with an approach that's slightly different from the climb to 20th level. Or perhaps, it's a back-to-classics approach after all. I'll post again when I've got it clear in my head.