John :
these guys in ACT can help :
there are two types of switch - not sure when they changed over
http://classicfalconspares.com/
you also see new ones on ebay
re XM ID plates -sounds like you need to hook up with gxlr380: see this link was asking the same questions ( but no answers as yet)
http://www.fordforums.com.au/showthread.php?t=11234185
brett
melb