Obviously without seeing the parts I can't say for certain but I suspect the cause of the chipped teeth is because one piston has a greater stroke than the other, this need only be 1mm or less to create a problem. The same thing can happen when a rifle is fired with seals that have reverted & broken up.
If you look at the rear cap beneath the top washer you may notice the washer beneath has a size stamped on it, this is to remove excess or reduce stroke so there's no undue pressure on the parts when assembled.
The parts are 15 & 16 on the factory drawing, unsurprisingly Chambers show them but don't list them.
Part 15 the one benaeth is a steel spacer for the To1 comes in 0.2 0.4 0.6 0.8 1.0 1.2 & 1.4
Part 16 is just the 0.5mm washer that sits on top.
IF IT'S NOT BROKE.........DON'T FIX IT!