I need to replace the closer spring on my horizontal cylinder. Is it exclusive to the Paso750 or are all of the 2v springs the same?

The 750 and 906 & 907 are all the same. The 900SS and Monsters through to the injection models have a different part no. but I think it is a design change and they are interchangeable as the rockers and heads are the same. I believe the later models may use a stronger spring. So any 2V closer spring should fit.

Little tip to get the rocker with spring installed; I only use a part from an old lamp, see left item on the picture below. It has a 5mm outer and 3mm internal diameter. Stick the end of the spring in and you've got enough leverage to fit the rocker with spring. Takes about 5seconds.. The right item I use to pull the axles of the rockers. Available at any local hardwarestore.
cheers Léon