I would inspect the distributor from the original engine for dust and condition of bearing. If the same conditions exist on the original distributor I would consider finding a known good distributor or a remanufactored, look on ebay for a reman. one.
IF the original does not have any indication of the grayish brown dust it would be a good idea, I think it would remedy your missing problem.
I am surprised that there were bent valves with a timing belt breaking as these engines are non interference engines and should not be any contact between pistons and valves when belt breaks. Unlikely a compression test was done before removal. Were the heads removed to determine that valves were bent?? Do you still have the original engine?? I believe someone gave you incorrect info on your old engine.
The dial you are referring too is called the camshaft sensor.
When you replace the distributor either set number 1 clyinder (front clyinder"closest to passenger tire" on the head closest to the firewall) at TDC of compression stroke or mark the distributor housing and engine for same location placement of distributor housing. Also mark the rotor location before removal and install at same location. You will need to check the timing once the distributor has been installed with a timing lite.
You can also look up the procedure in the online service manual.
Glad to be of help and don't be afraid to ask other questons if any, that what this forum is all about, to help each other.