It appears under the clan section in the TRO, so wouldn't that mean its just clan? otherwise wouldnt it be with the I and II at the end since there were no IS Lola IIIs for the era listed.
No, because that section provides stats for both Clan and IS tech versions of those ships. Going from memory, only the Fredasa, Liberator, and Nightlord are purely Clan.
Also, the Devs have made it very clear that the 3057 art does NOT depict solely Clan vessels, but both Clan and Star League ships can have that look.