Brake Support Assy. Seal?

[squirebill]

1949 Plymouth suburban.  So I took off the front brake wheel cylinders to inspect/rebuild them at the bench.  In the process also took the brake backing plate off. ...actually it fell off.   I always referred to this part as a "backing plate" but according to my parts manual it is actually called the "Brake Support Assy."  Who knew?    So in the process of cleaning off years of caked on dirt off the back of this plate (got a full cup of it) noticed a round metal piece spot welded to the center of the plate on the inside.   It's got an outer flange at the bottom where it is spot welded , comes up about 1/2 inch and then has an inner flange at the top. Seemed to be loaded with oil soaked dirt that I cleaned out.   Does anyone know what this part is for?  Looks like it might hold some kind of seal but nothing is shown in the parts manual.  The inner nose of the brake drum hub looks like it extends into this hat section. Also, this nose of the drum hub looks to have a machined surface on the OD.  Maybe a sealing surface?  Just wondering if anyone might know why Mopar might have gone to the effort to spot weld this piece to the backiing/support plate and machined the drum hub.  Maybe someone is familiar with another application where a seal is used with these parts. Regards   

[dpollo]

some had a felt ring in this area.  some didn't;.  I just did brakes on a 52  and there was nothing there  except the shape of this area had prevented oily residue from 

leakage around the hub seal from running down the "brake support assembly"  and contaminating the linings