As I recall it, you can disassemble the L2Tv2 tailswitch assembly and take the switch component out and put it into the P2D tailswitch assembly. You get the forward clicky with the P2D tailswitch, but some people like the results and some don't. I didn't like the combination of the forward clicky on my L2D100. Love it on the L1Tv2.
The L2Tv2 tailswitch assembly should fit on the L1D.