My 73 didn't use those screws for the ECU, voltage reg, starter relay exc... Mine have the loose washer. Some of the bolts also have a I/S on the head and not an anchor. My car did use those screws to hold the plastic starter shield and K-member shields inplace. I went with R/T Specialties for all the fasteners that weren't good enough to reuse. Also, you can soak the fasteners in muriatic acid. That will derust them and remove all of the old zinc plating. THen just send them out to be replated. It's a lot cheaper then buying all new fasteners.
Is Bill still selling parts? On Moparts he said that sales have slowed WAY down and that his priorities have changed. I hope all is well with him.