The only specific information I possess is where the 2R Marauder appears on the master unit list. It gets added to the Taurian List (and nobody else in the inner sphere) during the Jihad era. During the Republic era it's still on the Concordat list, but also ends up on the Canopean, Marian, and Mercenary lists (also Raven Alliance, but that could be a carryover from its time on the clan lists, or a sign of export).
Objectives periphery also tells us that the Taurians were building some sort of Marauder on New Vandenburg after the jihad, but it doesn't mention which type.
Even so, I think it would be a stretch to say that someone else was building the 2R for the Taurians when they had a functioning marauder factory and nobody else was using the type.