[Patrick]

If indeed it is a 44 bulb you may want to use a 47. It runs a bit cooler. Some sets have the bulb very close to plastics dial which can be problematic. You may have seen sets with brown or black marks on the dial. Those can be burn marks  from the bulb.
The voltage for the bulb is usually connected in parallel off of the heater winding on the power transformer. Where you could run in to problem is if your set powered the bulb off of the AC line though a balist tube or the heaters strung in series. Your set doesn't. In this type of circuit the voltage and current are very important. Wrong bulb can burned out( usually very quickly), damage the balist tube or other tube in that heater circuit
GL
Terry

Even though the schematic doesn't show it, I've got three lamps in series off of the heater windings. Still use #47?

Pat