They are an ML party, although they do descend from the WWP, which was not ML, certainly their current formation is ML. Brian Becker, one of the founding members, did an amazing series on Lenin you should check out if you are interested in seeing how leadership views Lenin: https://www.youtube.com/watch?v=ksimAtKX9jo

they self describe as a Leninist party.

Party for Socialism and Liberation is a Marxist Leninist party in almost all 50 states! Please check them out.