725's came out in 1929. The date stamp is when it was serviced. Nice looking machine. Could use a black bag. ChicagoMike (here on VL) is making reproduction bags for that very machine with the correct orange "Hoover" font on the front of the bags. He took one of my original 725 bags to get the graphics correct. Congratulations on a wonderful find.
I think rebuilds changed the emblem tag, the bag, and the switch. I have a rebuilt one and it's all been changed. They also put the bag on upside down.
I think this was the 'scary Hoover' model that was in the basement at my grandparents' house when I was a kid. I wasn't afraid of it standing dormant in the storage room but the idea of plugging it in and turning it on scared the hell out of me. It had come from my great-grandmother's house and my grandparents didn't use it. Their regular use machine was an Electrolux LX. I'm not sure what eventually happened to either of those machines but the LX was still in service when my grandfather left the house to go to assisted living in 1998, five years after my grandmother passed.
This one reminds me of the babysitter's upright when I was little, BIG black bag, first time ever a vacuum scared me too. Old house, plug was by the door where a light switch would be, sideways single outlet