[Texasrocker]

If the extra capacitor ,(in question),.. you found in your set isnt on the schematic, delete it. Unless you get hum from the B+ thru the shadowmeter coil after full electronic restoration, the .25uf bypass cap most probably isnt necessary at all. Recheck the schematic closely tho. Sometimes, the orig assembly-line techs would use whatever caps they had handy, and if it was quitting-time ( 5:00) pm at the old Philco factory in 1936, anything "spare" could have been used, in weird places indeed!? Ive run across many such scenarios in many mfgrs sets that didnt "sum" with the schematics before also! Hope this info helps.
Best of luck in restoring your vintage Philco!