Actually, there is no such thing as a para model. That's because the Swiss don't have a para unit
(just small Special Forces). The one you're thinking of is the M48-62 used for mobile troops and it is widely (and incorrectly) referred to as "para". It was heavily influenced by the British "dispatch" helmet used by motorcycle riders. The M48-62 was largely phased out after the M71 came into widespread use.
If you need a helmet cover I have several new and very good used condition available to hopefully match whatever size helmet you have. If you're interested, check the markings inside and see if you can pull a size number. It should be expressed in metric, such as 56-58 or something like that.