Well, since we're hijacking.....is the top of the old 4-Mile in a different location from the top of the current 4-Mile? If so, how/where did the Ledge Trail connect with 4-Mile (or did it just run along the current 4-Mile to Glacier Point and didn't ever connect with the old 4-Mile)? I just did Sentinel Dome last weekend (taking the old parking loop road that was closed in 1970 rather than the longer "official" trail) and climbed it from the valley side to avoid the hordes of college kids from Cal that were in a large group going up the official trail. Wasn't there an old trail connecting Sentinel Dome to the old 4-Mile Trail (downslope from the current trail between SD and Glacier Point parking lot)?
As for Old Tioga, yes, the original 1883 road was largely in a different location from the current alignment from Cathedral Creek to Tioga Pass. The current road was (as I'm sure you know) realigned in 1934 as the first of the three segments of Tioga Road reconstruction. I've hiked several individual portions of it, but not the entire segment in one go. The first portion (west to east) criss-crosses the current Tioga Road a few times between Cathedral Creek and the western end of Tuolumne Meadows, but enters the meadows just southwest of the current roadway (a piece of the old roadway is buried in a thick forest on the right side of the current road as you curve down the hill to enter the meadows). West of Cathedral Creek, I've never been able to really ascertain exactly where the old roadway was located between there and Tenaya Lake. I think much of it was destroyed in 1960-61 when the current road was built, but generally think it was to the south of the current road. There's a large quarry area that dates from the 1960-61 construction work, on the south side of the current road about 2/3 mile west of Cathedral Creek, and that's about as far west from Tuolumne Meadows as I've been able to trace the original alignment.
Anyway, going eastward, the current road was placed on top of the original road along the southern edge of Tuolumne Meadows going east to where the Soda Springs trail curves off to the northeast -- this trail is the old Tioga Road, which bridged the river where the current trail bridge is located (I think the abutments date from the old Tioga Road). The road then curved to the east (it did not go through Soda Springs, at least in its final incarnation) and continued along the current closed road into the access road for the Soda Springs/Glen Aulin trailhead, which is the old Tioga Road east to the junction with the current road. From there, the old alignment continued straight across the current road to its south side and followed the current bridle trail east (the old road through here was torn up in 1970, leaving just the trail now). The old road follows the trail to the current JMT parking lot and then continues into the modern access road for Tuolumne Meadows Lodge. The old road follows this to the point where the current access road curves to the right. Straight ahead is a service road that is the Old Tioga Road. This road starts climbing the grade out of the Meadows area -- where the service road curves to the right, the old Tioga Road continues straight up the hill. This section is in bad shape and not drivable. The old road continues up this grade, intersecting the current road at the big road cut where it meets the Dana Fork. From here east, the current road buries the old alignment for a short distance. Eventually, the old alignment veers off to the north of the current road and this segment is easily hikeable as they did not try to obliterate it when the new road was built. Pieces of old pavement show up along here, which surprised me somewhat as I had thought that the Tioga Road wasn't paved until the new segments were opened in the 1930s -- and that the central 21-mile segment wasn't paved until the late 1940s or so. But asphalt pavement definitely exists through here. The old road passes by some sort of concrete platform (just to its south) that I'm not sure what was for. After that, you have to cross Gaylor Creek (I saw no signs of the old bridge/culvert where the road crossed it), and a long straight section of the old road continues northeast, striking the current road near the Mono Pass trailhead. Where the current road curves to the north, the old road continues straight (to the NE), emerging into the open meadow and climbing to Tioga Pass to the east of the current road, meeting the current road just before the pass summit. From the pass, the original Tioga Road curved to the left from the current road and continued climbing to the site of Bennetville and the Great Sierra Mine; however, when the NPS bought the road, they abandoned this portion (which is now a hiking trail) and simply connected the Tioga Road to the new state road up Lee Vining Canyon that was built in 1918 (no road down the canyon had previously existed). That 1918 road survived largely intact until 1965 when the state completely rebuilt it down to U.S. 395. Several abandoned cut off fragments of the 1918 route down the canyon remain, and a couple are still in use as spur roads.
This is probably far more than you'll be interested in, but once I get going....it's hard to stop!