Most of the extendable tow bars are about the same in complication or, mechanism. While I've not had the opportunity to rebuild any Roadmaster Falcon models, I've had both my Blue Ox Aladdin and, Blue Ox Avent II completely apart, down to the last nut, bolt and roll pin.
The locking mechanisms are actually very simple in operation. The only stumbling blocks were knocking the roll pins out. They can get stubborn if they want. My last one, the Aventa II, one of the outside tubes was slightly bent so, I straightened it out and, had to weld up a couple of feet that were drug along the road 'till the owner got the rig stopped.
After all the repairs were done, I had all the appropriate pieces powder coated and, then as I was re-assembling it, I installed a brand new shim kit. Now, it's better than new. I've got a whopping $60.00 into that one.
If you've got any DIY in you, you'll have no problems what so ever in rebuilding that tow bar. You'd be amazed at how simple they are.
2004 ITASCA HORIZON 36GD, 2011 GMC Sierra 1500 4x4 Toad '08 GL 1800 Gold Wing
Retired-29.5 yrs, SDFD, Ham - KI6OND
Me, Karla and the Sophie character, (mini Schnauzer)