Check! Gravitational time dilation from Earth: Δt' = 1.00000000068664 seconds (clock runs faster) Gravitational time dilation from Moon: Δt' = 1.00000000003152 seconds (clock runs slower) Lorentz time dilation from Moon's speed: Δt' = 0.99999999999419 seconds (clock runs slower) Combined dilation effects: Δt' = 1.0000000006493 seconds (clock runs faster) = 56 μs per Earth-day

Thanks, I was expecting something fundamental like that. So presumably, the diff between your 60 μs and the oft-cited 56 μs must be due to the lunar gravitational and Lorentz dilations. I'll run the numbers and report back if they don't work out. But I fully expect they will.