Starting with the easy point, the main potential concern with the sharpening is that burrs could have been left on the cutting edges, which has much the same effect as bluntness. On the bedknife, the edge facing the front of the mower is the cutting edge, and its front face is likely to be at right angles to the top surface (the one that has just been ground). The cutting edge is the most crucial aspect of the cutting process; it has to be sharp and burr-free. Then, the grass is swept onto the cutting edge by the many blades on the cylinder. The cylinder therefore rotates toward the bedknife cutting edge, and the leading edge of each of its blades has to be as sharp and burr-free as the bedknife. So, all of the cutting edges in play are usually right-angle edges - but some sharpeners like to "relieve" the contact area by cutting away behind the cutting edge, like the clearance angle on a drill bit. I won't get into the pro and con arguments on this, but if it is done it means the edges may not be precisely square.
The bedknife cutting edge and the cylinder blades'cutting edges are where the cutting occurs, and they need to pass extremely close to each other. This is the only point where near-contact should occur.
If your bedknife adjusting screws are made in the simple and obvious way, there is a female thread in the fixed bar the adjusting screws pass through, and a lock-nut to keep the screws from drifting out of adjustment. Most people tighten the lock-nut far too much, which mangles the threads of both the adjusting screw and the fixed bar. Over time the screw becomes loose in the fixed bar, and adjustment becomes a real pain. From what you have said, you have some pronounced but very localized damage to the threads right where they are normally engaged for correct adjustment. There are two alternative cures for that. One is to tap the fixed bar to a slightly larger size and fit matching adjusting screws. That means you end up with metric or A/F adjusting screws, which is convenient but not original. The other way to go is to helicoil the fixed bar and find some new screws of the original size. Realistically you will not be able to get screws with Whitworth heads anyway; they are obsolete.
