I've not sent mine back, but I have contacted SA. This was their reply, hope this helps.
"Thank you for your interest in Springfield Custom services!
Cost to checker the front strap, 30LPI, would be $250
for hand checkering or $140 for machine checkering. (Machine checkering
is rougher than hand checkering and may also have some burrs and overruns
compared to hand checkering.) Your lightweight frame will need to be
refinished after the checkering is done which will add an additional $100 to
the cost of checkering. Return shipping and handling charges when the work
is complete would be $30. Estimated turnaround time would be approx. 8
weeks from receipt of the pistol in our shop for the work.
Custom Shop Coordinator
420 West Main St.
Geneseo, IL 61254