Key thing is that the back table needs to be exactly the height of the knives. The front table needs to be slightly lower, on my Powermatic, it's 1/32nd. You don't want to take off very much per pass.
I found a magnetic jig years ago that sits on the outfeed table and has rods that thrust forward over the knives. When installing the knives, you adjust them so they just kiss the rods, then lock them in. I don't alter the outfeed table's height adjustment at all. Here's a link to the jig.
https://www.rockler.com/rockler-mag...in_A&msclkid=c1beb577568912d454d4d40fbe7242af
You want to make sure the iron is clean and dry, then apply paste wax every 6 to 12 months, depending on humidity in your area. I keep mine covered with a light canvas sheet so it wicks away any moisture. The fence requires the same treatment and I suggest you get a Wixie digital angle gauge so you can set the fence exactly 90 to the tables.
Not sure where you will find the knives. But if you find some that work, get a couple of sets of the steel type. With some machines, if you get a nick in one blade, you can shift it over slightly and the other blades will pick off the raised line on your workpiece. I wonder if ereplacementparts.com would have either the knives or their exact measurement.
Knives are kind of expensive, and yes, they can be sharpened. There are special jigs just for that purpose. LIke this:
