Wow - that collar is certainly different compared to both my stock units. Mine are much smaller - more like the size of a nut... and they were not pressed - just "snug" - I got them to slide off by hand. Maybe some WD-40 on the shaft will get it off.
I'd say those marks on the wheel are certainly not good. Neither of my units show that. Also - I'm going to take a closer look at the bottom "bushing" before I agree or disagree it Kato...
OK – here’s what I found. The dist. shaft is held firmly in place at the top by the dist. housing bushing/sleeve (which measures ~ 1.8”) and the block bushing/sleeve at the bottom of the shaft (where it meets the oil pump driveshaft – block sleeve measured ~1.15”.) The bottom of the dist. housing and shaft have huge clearance – which means the bottom of the housing is not a “wear point” - and plays no part in holding the shaft in place (or keeping it from wobbling.)
Here you can see the shaft/housing clearance at the bottom of the (brighter aluminum) distributor housing.
I “tested” how snug the bottom block bushing/sleeve was by seeing how much wobble or slop was at the top of the free-standing dist. shaft(s.) I got ~.050 with my old, and .042 with the new.
I then added the housing. This proved my old unit had some wear compared to the new. The old housing and shaft measured .002 (two thousandths.) New housing and shaft may have measured .0005 (half a thousandth) but I'm not sure as I was yanking/pushing/pulling pretty hard.
It appears to me that Ford designed the stock 5.0 distributor to have enough clearance between the shaft and dist. housing bushing to allow for some oil lubrication/splash to reach at least the bottom of the shaft/bushing. (My old unit had lots of oil-buildup inside the bottom of the housing.) The shaft also has a spiral groove cut in it where it rides inside the bushing – this groove spirals in a downward direction which appears it would keep oil from reaching the top of the shaft and filling the inside of the distributor.
It’s my guess Ford distributors came off the assembly line with a wide range of “wobble” tolerances - from almost none to “significant.”
IMHO – a little “wobble” at the base of the housing while holding it in–hand is irrelevant – because once you stab the dist. in the block and “plug” the bottom of the shaft into the block bushing – all wobble is virtually eliminated.
I think a better distributor bushing “wear test” would be to check if you can feel any free-play (wobble) at the top / rotor-side with it in the block. As I described in the 3rd photo - my old unit has very slight movement - I could feel it. The new unit may have .0005, but I can't feel any play. (Again, while holding the new unit in-hand it does have slight wobble/play at the bottom.)