Good question. The differences revolve around the circuitry, not the pickup number or placement.
Until recently, expect for the E series L-2000, most L2ks did not have anything that really equated to the Wunkay's "OMG switch." Some more recent L2ks were wired with what I believe was called the "K-switch" circuit, which approximates the old "bass boost" from the 2000E, but by then the preamp had changed quite a bit, not to mention the MFD pickup had evolved, too.
So, the answer to your question is... Yes, if you have an old L-2000E, the differences between that and an old L-1000 are pretty much the extra pickup. Otherwise, the evolution of the MFD pickup and the L2k preamp have mitigated those similarities significantly.