I purchased and have received a CEV 5421 tail light from the following vendor, who specialty is Italian motorcycle parts, mostly street bikes. His web site has fuel petcocks and Marzocchi and Ceriani suspension parts. Back to the beginning of the post, he believes he may have 3 to 4 more of the cev lights. I paid 30 dollars for the light. Wolfgang, also thinks he may be able to find some more, but they may be some what more expense.
ps: I just received the rear enduro fender from Larry. Great repo.
catalog
http://www.angelfire.com/biz/laverda/itcatalog/mainframe.htm
cev light
http://www.angelfire.com/biz/laverda/itcatalog/l3.htm