I don’t think the first-generation horns lasted until 2007, since this archived page from 2003 lists -HO (high output) and -P (piezo) models, but not -H (first generation horn) models. Both the -HO and -P produce a sound that resembles the -HD, which was released around 2003 together with the multi-candela strobes based on this archive. This 2003 update also appears to be the first time FIRE lettering was introduced to the Genesis horns.
Oh, good find! Another piece of the Genesis history puzzle found I guess.