During my move to Alexandria, my Rena 400 was dropped and the right knob busted off. Now I cannot control the volume of air out the right side (which is currently in the "off position"). I tried super-glueing another knob (because the orginal was lost) to the right one in hopes that I could once again control the air coming out the right side, but no luck. My question is, is there somewhere where I can purchase a air control knob for a Rena 400 and would it be possible for me to fix it myself? Thanks