Manualblock,Lafayette LA-215 schematic shows PT with a very similar winding to what you mention:
6.3V 2.7A
6.3V 2.3A
6.3V 0.3A
130V DC 0.16A
130V winding did use doubler and fed 255V DC to EL84 single ended output stage amongst many other things (seems fairly common to Lafayette design).
Perhaps LR300 was single ended EL84 also?