Turn Signal Relay

[Sonny8oy@AOL.COM]

Yet another question:
Part I
Ordered a replacement turn signal relay for the Squareback.  Went to install
it today.  So awkward to get at.  Anyway, the new one is an aluminium
cylinder, the old one is a plastic cuboid.  They're both 4 pin, 12 volt, and
it is the right part according to Rocky Mountain Motorworks, where i ordered
it from.  Assuming it's the correct part, it should just be a straight swap,
right?  However, the old one has a colour-coded piece of paper over the
prongs, the new one says P, X, L, and the 4th pin is blank.  Can someone
translate please?  Also, does the relay unit need to be ground, or is that
taken care of by the 4th pin/wire?
Part II
In the process trying to do the above, the emergency flasher switch came apart
and fell into a dozen corroded pieces, so I'll need a new one of these.  Does
this being inoperational prevent the turn signals from working, because after
I rewired in the old relay (which allowed 3 out of 4 turn signals to work [no,
it's not a bulb problem]), none work now.
Part III
Why is it when I try to fix something, I create a bigger problem en route?
(Although I did manage to put in new sunvisor clips without punching a hole in
the roof....)

Thanks everyone

Sonny
dried-out '69 Squareback Auto with no turn signals