Here is a site that has the basic LK201 data:
Allison
One of the most comprehensive LK-201 (and DEC mouse) references I am
aware of is the VCB02 handbook; specifically Appendices B (LK201) and C
(mouse).
http://www.bitsavers.org/pdf/dec/qbus/VCB02_PrelimHwRef.pdf
N.B ~23 Mby pdf - consider downloading from a mirror
Martin