[Electronic M]

Most sets have more than two B+ rails (the lower voltage ones are usually derived from the higher ones with a voltage divider). You need a SCHEMATIC to know where to measure and how much voltage should be at such point....Otherwise you are going to just spin your wheels guessing. Until you (or any would be TV restorer for that matter) have at least 10 tube TV restos under your belt it is usually futile to troubleshoot a set WITHOUT a schematic (even with our help), and even those of us seasoned enough to do most work blind sometimes have check a schematic to know how aspects of a given set should be.

Check with libraries in major cities in your region, and libraries at technical colleges/vocational schools....Odds are one of them has a free sam's library, and for the cost of photocopying you can get the service data. There is such a place 15 minutes from my house (they only keep mid 60's and later sam's), and a more complete library in Milwaukee about a mile from my old College.

147V on a 150V rated cap seems high....If that point is at the doubler and there is a resistor or choke between that cap and the circuits loading the B+, which is going open then it would explain that odd measurement and low B+.....If your set uses a doubler it could also signify the other doubler cap failing.