hey Floridian Kirby guy,
That's a 70s Kirby replacement bag, I'd recommend you take the bag off it's emptor, turn it inside-out and vacuum it thoroughly. Instead of a machine wash, if you're not afraid to get dirty, I'd also recommend hand-washing the bag. I've done this before with a replacement bag on a now-parts 1-CR,packed and bloated to the brim with nasty old dog hair,came out nearly to clear!
Simply use a soft scrubbing brush and some dish soap in a sink or outside, fill the bag with soapy water and pulse it up and down, like a agitator in an average automatic washer, only gentle!
Remember, filtration quality and overall ballooning of the bag will drop after washing, as washing allows more air (and sound!) To pass through the bag. After extensive use the bag should begin to plug up, thus returning the filtration quality and beautifully large ballooning of the bag!
The 512 could use some polishing while you have that bag off!
Good luck fellow Floridian Kirby man!