DADDY GLOVES: over in the slow lane I thought about your total investment. You said you might get a wash or a really really good price for the jointer. If that's the case and you have the cutterhead issue, why not upgrade instantly for easier maintainence of cuts and a quieter machine. Just buy a new cutterhead but with helical replaceable carbide knives.
As a start on that thought try this URL for a price on a head to fit your machine.
https://www.holbren.com/byrd-shelix-jointer-heads/If you sort by mfg name you will get a page with POWERMATIC cutter heads and you will find one for the model 50 for about $330. Some wd40, elbow grease and a weekend of cleaning etc with the new cutter head you could have an enviable machine. A new mod 54 would run about $1500.