I did not buy any special tools to service my air2. I believe I used a flat blade screwdriver or two to unscrew the cover the first time. Now I can usually get it with my fingernail. I did make a spacer to fit in the inlet tube with the orifice removed to help assemble the demand valve in the housing. The spacer just pushes and holds the demand valve stem and spring in the housing so the insert, lever, washer, and nyloc nut can be attached. Then I remove the spacer and install the orifice and LP seat. As I recall, I cut the spacer from an old plastic pen.
Generally, you can usually find a work around for most special tools or fashion your own. Your 108 and 109 should be fine with std shop tools. You will probably need a yoke nut socket. I made my own with a dremel tool. Pictures in my gallery. You will need pin spanners to remove the ambient chambers from the 1sts. Again, homemade is possible. I think I started with a cloth strap wrench with a bolt through the material to engage a hole in the cap. You will also need a pin spanner to to engage the 2 holes in the HP seat retainer. I started with a pair of bent nose needle nose pliers that did the job OK. I did buy the bullet tool to insert the piston in the Mk5 without damaging the HP o-ring. But I'm sure a work around for that would not be difficult. You will want a good set on o-ring picks. The HP o-ring in that Mk5 and the o-ring in the LPI connector are 2 of the harder one to get at.
