[Richard]

Here is the info I collected while redoing the brakes on all three axles. I will post the most important info and links first, and then more detailed info and pics relative to each axle. 

Key info. You can use this info to cross reference and utilize other sources. The parts are pretty common.

Front brakes
Knorr Bremse SB7 series. Pads are easily available with just that information. I got mine at NAPA. 
Front Rotor Meritor M44DII37415 Sourced at Find It Parts
Oil Seal Scotseal 46305 Plus Sourced at Prevost 

Drive Brakes are 16.5  diameter Q Plus, 7 inch wide. FMSI 4707Q. Again, bought at NAPA
Drive Drum.  Webb 66884.   NAPA
Oil Seal Meritor 1205 V 2492 Sourced at Prevost

Tag Disk Brake is Meritor ADB 1560
Pads were Carbomet MD268 sourced at anythingtruck.com EDIT: Although the brake pads fit, I found out after a few years that they had small but important machining differences in the way they fit. The correct pads are https://www.finditparts.com/products/395...kit15626pm

Tag rotors were fine and not replaced, although both the rotor and the pads are asymmetric leading me to believe they were severely worn before I read the manual. 

I was intimidated at finding the parts because I knew of other gurus who had paid dearly to have truck shops find the parts. My strategy, since I had the time, was to remove everything on one side to hopefully aid in identifying what I had, and finding the parts. I bought everything I could from NAPA so I could compare the old part to the new before paying. This stuff is heavy and freight back and forth will kill you if it’s not right. Tom, had also planted a seed some years ago when Leo had replaced one of his rotors. Leo said just like Prevost. That led down the path of sourcing from Prevost since they have a branch less than an hour from me, and a very helpful guy at the parts counter. 

First chuckle at my expense is that you must forgive my typing errors. Did you know that the tires are heavy enough to break your finger?