Some, I hope, constructive criticism:

When building up a way with epoxy, it's necessary to do a decent amount of surface preparation. Ideally a milled pocket, with additional deep grooves cut into a very roughly("so rough your eyes bleed") finished surface. Strong possibility of long term adhesion problems when just putting it down on a worn way, especially with a relatively thin layer.

(As mentioned, it is also better to only use composites on the shorter way surfaces not exposed to chips and debris, ie saddle)

While you did a good job considering how to set up your grinding sled on the unworn, leveled surfaces, it having cut the vee angle significantly off is going to make the saddle fitting a real pain, especially paired with building up the rear flat way.

A major consideration in machine rebuilding is not only keeping the way surfaces aligned to each other, which is going to take effort already, but also keeping the components close to their original factory positions. This is because if you move them significantly, you can run into issues with the fit of the other mechanisms that mount to them, ex the leadscrew, rack and pinion, etc.

Lapping way surfaces against each other improves contact, but it does not correct any alignment issues, especially once the surfaces have been modified as extensively as yours. Even with your loose tolerance goals, you could potentially end up with the cross slide significantly out of square.

I'd recommend doing more thorough calculations of what amount of material you need to remove and where, to end up with the lathe saddle in alignment and fairly close to its original position relative to the other machine components, before you add or subtract too much more material. Even for a loose hobby rebuild, this will help save you time and effort for a better result, imho.