I have always found it a chore to have to use a spanner to move my tumbler reverse (the gremlins insist on hiding it) so have updated it to the more usual modern design.
A simple job to do after facing one side of the lever and bolting a small steel block pre drilled for a spring loaded plunger which also serves as a drilling jig to drill three shallow holes in the casting after setting the mesh of the gears.
While at it I noticed a lot if play in the spindle part of the reverse cluster so ball races were fitted in place of the plain ones. The reverse gears were also very worn and noisy and were wearing the integral mandrel gear so two new ones were made from Tufnol, a Belleville washer under the original clamp bolt gives a bit of tension.
All these parts are less used these days since fitting a power lead screw drive instead of using the gear train for fine feeds, and are now only used for screw cutting but it was still worth the mod.