Thanks for the posts! The reason I believe these are the early hot L-500L and L-500R pickups is that that they they are crazy loud.It almost sounds like the guitar has a built-in pre-amp. The bridge pickup seems to have way more output than the Dimarzio Dual Sound pickup I have in the bridge of my Rick 480. Also,they match the description of the early versions I found on the
Bill Lawrence Review website
They have chrome housings, 2.150 inch long curved blades and there is no imprint on the back like the post 1981 pickups
"The L-500 magnetic electric guitar pickup was released by Lawrence Sound Research (LSR) in 1979. Inheritor to the L-90XL throne, the L-500 was the next stage in the evolution of the ultimate guitar pickup by Bill Lawrence(Willi Lorenz Stich). Initially available as Lead/bridge (L-500L) with 9.6 Henry and Rhythm/neck (L-500R) with 4.8 Henry.
The L-500 line would grow in 1981 with the creation and annexing of the cleaner sounding L-510L pickup. Some renaming ensued and by the end of 1981 the hot original L-500L was renamed the L-500XL, with the cleaner L-510L becoming the new L-500L. The L-500R did not change in name or design and the L-510R was dropped for the time being."
