Please help to identify these two MEC 600 jnr Charger bars

I have two MEC charger bars which work well with the press, but cannot identify them as neither appear in any MEC lists of charger bars I have viewed. The RED is clearly for a single stage press and probably the silver also as the external measurements are the same

First this red bar, stamped on one end 302 12 G A 6 PA with a screw in bolt which intrudes into the smaller of the two "holes." Neither of the "holes" have a chamfer on one end to accept a powder bush..

Attachment 159629

Attachment 159630

Second is a plain silver bar with no numerical or alpha stampings. Curiously it has a threaded bolt hole for the "sliding measure stop on two opposing sides,whereas the standard charger bar has only one hole. The larger hole is chanfered to accept a powder bushing.I suspect it be be a "Home Made" bar for a non standard lead load?

Attachment 159631

Attachment 159632

Any assistance appreciated. Thank You

The top one is to allow varying powder charge weights by screwing in/out the long screw. The short screw hole is top provide a stop when sliding the charge bar back and forth from powder charge to shot charge. You will have to throw charges to determine the actual drops of powder and shot charges.
The silver bar has the lh hole recessed to accept a range of available Mec powder charge bushes. The rh hole is for shot charge and you will have to drop a charge through it and weigh to determine the actual shot charge wgt.

Woody is on to it.