the drop rate is extremely low, and depending on which version of cabal it differs. For example older versions with DT dungeon still drop cr2/rol2 in trogolo lair DT solo.
for newer versions that are in current episode and official servers, it drops in quite a few dungs, ft1, ft2, lostworld/forbidden island, sienna 1, sienna 2, ic1, ic2.
Maquinas Outpost does not have the rol2 listed on the drop list from cabal wiki.
Note: that drop list is slightly inaccurate because it does not reflect the changes to ft1 during most recent episode patch of official servers. FT1 no longer drops uchh, fchh, sehh, or +8 capes; Also does not drop terragrace/shineguard/mystic grade armor anymore, only crafted osmium epics, and crafted red osm weapon epics.