Hi Jerry,
The holsters had a separate base piece, against which the barrel would rest. In the tropics, the leather would expand and the pistol would bump around in the holster, causing wear to the bottom piece and the pistol itself (muzzle end and triggerplate). Note that most troops used horses and mules for transport.
Orders were given to wrap the pistol in cloth, before putting it into the holster! A practical, Dutch solution
There is also a rumor (I've seen no reliable confirmation) that the Portuguese contract holsters were quite good in order to avoid complaints like they had from the Dutch. I'm not exactly sure what these problems were, my guess is that the leather of the early holsters was not up to the moist tropical conditions.