The R&R labor for pulling that 722.3 (or 4 in your case - 2.6l) varies by body style from 5.5 to 7.5 in the 140 cars.
The proper reseal of the front pump will include the large o-ring that seals the cast iron pump body to the aluminum trans case. To do this the front of the trans has to come apart ( as the retaining bolts are inside the trans). We charge 3 hours for this and maybe another to disassemble and replace the reverse brake clutches.
We used to do a lot of those jobs but the labor is over half of the 16-18 hours we get for an overhaul. As the cars got older the value of such an extensive repair wasted away. Now, no matter how many miles, the time frame is so long that seals will fail at any moment. Most clutch or band problems started with seal leaks. It makes no sense anymore to just reseal the front and do clutches for 10 hours when the whole rebuild is 17. Labor being the greatest portion of cost.
Bosch Master, ASE Master, L1
33 years MB technician