I just went through my terrains folder ("choose terrain" on clipboard) just for kicks, and here's the MA list I found:
-baltic
-beta2
-compello
-donut
-equinox
-FesterMA
-Frac3
-mesaview
-mindanao
-mmesa
-ndisles
-ozkansas
-sfma
-SFTERR
-smpizza
-STALL
-trinity
Two of these maps I don't recall ever playing on (STALL and SFTERR). Mindanao might be a problem because map tiles are incorrect (as in Mindanao does not contain European terrain). It was refreshing to see donut, and wish it could be implimented again.