Yes, I think there were two different models, both resembling the French VB, the earlier one was shorter than the French model, 25mm long, where the new one was 38mm long and closer to the French version in length. The new one fired a new grenade apparently too (heavier), but I am not sure what the effect on range might have been.
Interestingly, the French did a study on these during the war, it was related to range and effect of the grenade when fired from certain angles. Apparently to have an effect, you really needed to know what you were doing, especially at shorter ranges, and know something of the intended target. Some of the tests showed that sometimes the grenade exploded too high for effect, or hit the ground too early and rolled along the terrain, before exploding. Ideally you wanted an explosion 2 meters above the ground.
There was quite a bit of interesting observations, discussing the great utility in both defense and attack, when skilled soldiers were using the rifle grenades.
MauserBill bought one several years ago on ebay of all places, very cheap too, as several of us stayed off the auction. It is a fairly difficult thing to find, as I have never seen another for sale, that I recall anyway. I have seen parts and even some period documents, that came with the grenades and dischargers, but the one time I had a shot at one, the seller pulled it, as he changed his mind about selling the papers. Couldn't blame him, as I have a thing for period documents and reports.