you should cast some of the tranq gun and knife/sheath he used in mgsv. you could use the pak one as a model. im interested in the holster, pm me with the particulars.
I bought one that looks similar and then the clips you get on the back of pouches, like the hot toys naked snake for the belt to thread through - I glued them to the back of the sheath so it functions the same as the pouches in terms of putting on and off a belt