The first Harpy's came out in the mid '80s. Stainless handle (with drying vent), Gin-1 stainless blade, tip down carry. The knife was designed to be a "rope cutting knife" for offshore workers. The steel was changed to AUS-8 about the same time the Melin liteweight version came out (tip up), also with AUS-8 blade.
The Merlin was discontinued for a while and has just been re introduced with ATS-55 and the new Delica handle with the L/R clip (tip ip).
The Harpy was changed to ATS-55 recently.
The G-10 version was something that I thought to try because I believe G-10 is such a versatile and functional material. The G-10 version was planned for and now has ATS-55 blades (although I believe their were a few G-10 handled versions with the AUS-8 stainless blades. Some of the G-10 Harpy's were tip up & some were tip down. The G-10 version will not be a standard item for Y2K model line-up. Hope this helps.
sal