This Lan-Cay got my attention.
 

I was checking ebay and one auction got me interested.
http://cgi.ebay.com/M-9-BAYONET-GREE...item35a4131f43
The hyphen in the blade marking, along with the bright blade color, seems to suggest a commercial variant.
But note the cutter plate color!
Much brighter than usual. :confused:

Carlo, from the looks of it, the blade, cutter-plate, & screws have a bright finish. It almost looks like the finish is cadmium plated (or maybe painted silver?)...

All of the Lan-Cay's that I have, that share that blade shape and markings, have oxide blades.

Greg I have to admit that after many years I still make confusion between all the different variations made by LanCay. :tongue:
In regard to the bright blades:
1. First style bright blade (with the "step" between the saw teeth and the guard/ with or without fuller): everything marked Lan-Cay (with hyphen) is commercial.
2. Second style bright blade (no "step"): everything marked Lan-Cay (with hyphen) is still only commercial.
3: Second style bright blade (no "step"): the only G.I. version was a small group marked LanCay (without hyphen).
Fabrizio posted pictures about this last variation (n. 3 above)
http://www.quarterbore.net/forums/showthread.php?t=2573
Hope to be correct.

Thanks Carlo. These LANCAY's are very confusing to collect, but I can't stop. I have to admit, I was a little stumped by the one in the ebay auction. I knew that there was some information on the commercial blades somewhere, I just couldn't find it. The only book I have that shows the LANCAY's is AMERICAN GLADIUS and it didn't show the one on ebay in the book. I just know that I don't have the bright blade without the step, I just need to make sure it doesn't have the hyphen. I'm sure that the GI one would sell for a whole lot more than the $66 that the ebay item sold for.

Take Care, Greg