Why were the injection pump and injectors being changed in the first place?

Were there any marks on the tops of pistons where the valves hit?

An injector pump out of time won't cause a bent valve.

The cam to crank timing would have to be affected in order for valves to bend. If cam to crank timing is out, all intake or exhaust valves will bent because they are open as a piston is coming up. If the timing chain comes off and cam stops turning , only a couple of valves are open and only those bend.

With the cams out, are the bent valves still not seating?

Did you stick anything in the injector hole to find TDC at any point?

With a bent valve caused by an outside source, they generally get better not worse as the valve hammers straight again.

Does the machine shop know the history of this head and to look for actual causes of damage?