There's probably a good reason that Ford plow's points/shares, and moldboard look so good, with the welded hitch. It didn't work so good. A lesson I learned a long time ago when going with uncle's and buddies plow shopping. They'd always look for the one's with those items well worn for two reasons. One reason, it could be bought cheaper, but the main reason, that plow would plow well. That's how it got in that shape.
And rule of thumb around here is, with whatever width share you end up with... Plowing depth is usually set at half the share width. Around here, topsoil thickness varies quite a bit, so most bought plows using that formula, to plow just deep enough to turn the topsoil, not so much on share width, as far as determining how much width was turned.
And I'm not quite sure I understand why someone would want to plow much deeper than that. Most crops I know of grow in 6 - 8" of prepped soil. Any deeper, and you're only making the hardpan further down, and harder to eventually break up. If ever it comes a time you do develop a hardpan, getting a subsoiler, and running diagonal to the direction you moldboard plow will break it up. Much easier to pull one at 9 - 10" deep, than 16 - 18" deep. Plus the fact running way deeper than it was designed for, you loose what I would refer to as the action of the moldboard. Dirt literally going over the top of the moldboard, instead of being turned over, to cover the previous crop residue. It took me a while to convince a buddy of mine who moved out from town, and was complaining of how badly his little A-C CA tractor and plow were doing such a bad job of plowing. It took all of 20 minutes to get it adjusted to get it to plow like it was intended. It would have probably taken less time if he'd been paying attention, and stopped when I wanted him to, to readjust. Just mesmerized buy the turning dirt I reckon'..., LOL...
Also look real close at used plows for bent beams, coulters on it, tail wheel condition, if it has one, etc. And when you find one, and start plowing, go a little slower the first year or so, in case you do find some sizeable rocks, at least on top. Around here, there have been a few work up closer to the top through freeze and thaw cycles over the years. A plow with a bent beam is about worthless.