Originally Posted by Philip
Hilt appears to be a variation of AVB Norman's Type 61, pommel is his Type 29 and he does note that these two types tend to appear together on many rapiers. His chronology of 1600-40 for the hilt seems to match what we have here, and he notes several variants on the essential Type 61 theme on a large body of surviving examples -- including the C-shaped terminus of the knuckleguard.
What is interesting to me about this example is that the position of the guard seems to be reversed, i.e. designed to protect the left hand. If so it might explain the shortness of the blade. Could this not have been designed for an unusual fencing system that employed a shorter sword in the left hand, as opposed to a main-gauche dagger? There were schools of rapier fencing that called for identical rapiers in each hand (spada da lato gemelle), analogous to the Chinese technique of fighting with shuangjian, or a matched pair of swords. (see Boccia/Coelho, ARMI BIANCHE ITALIANE, 555/556 for an example in the Odescalchi Collection). So here, we may have the surviving weapon of a set of rapiers using a shorter blade for the left hand, which again has a Far Eastern counterpart in the combined use of katana and wakizashi in the "niten-no-ryu" technique.
In fact, there is a woodcut illustration of a fencer with two rapiers, the one in his left hand being visibly shorter albeit with the same blade width and taper, from Marozzo's OPERA NOVA (Venice, 1550) showing the technique of combat "alla due Spada" (published in LIVRUSTKAMMAREN, Vol. XIII:5, 1974, p 193, fig. 13