I never said that, the first versions, 8Z, were built from Alshain's New Olson's plant in 2739 with original LL as a SLDF commissioned Mech. Problems with the main weapon prompted a swap for the Lord's Light PPC, it's replacement meant that for the next 35-ish years, it could be considered a " Royal " mod. Up and unto the Exodus, where House Kurita took over and produced this exclusive mech for themselves. The 8Z was upgraded during the many various conflicts that arose, losing the " Royal " name attachment.
Not till the Second SLDF did this mech get that name again... the 12A, built with clanrech... for an IS power.
Those are the facts I've gleaned from my personal pursuit of the game.
What defines a Royal mech? In my eyes it's the ability to dish out damage faster than one can absorb in as little time as possible. The 8Z was a production model, until the weapon swap... then it became common place during the 1-4th SW...
TT