Linn arms do have the correct geometry for use on the L75 Jez. You merely need to drill the three mounting bolt holes.
I have a few Lenco turntables (in various states of assembly) and have purchased an LV-V to use on one. The LV-V being the only Linn arm with a universal/SME fit removable headshell and highish mass, making it suitable for use with most MCs (and Deccas). The bearings and general build quality are decent.
You previous L75 experience makes me think it must have had mechanical problems. Good examples of these turntables are very quiet and rumble free normally. Maybe somebody lost the ball from the main bearing that bears upon the thrust pad. I've seen that and it wrecks the quiet running.
It is impossible for anything digital to sound analogue, because it isn't analogue!