Hey Wood Chips,
Mine has the old "armstrong" adjusters for belt tensioning. Did you ever consider "dumping" the air system and going back to the manual system? I know then your "stock" length arms will do the job and you won't have to buy those six new "dammit" tools to carry around with you.
Seriously, I hope all works out in your repair. If you need some longer arms I can make a run up the road tomorrow as it is a national holiday. Just let me know where I need to come.
Will