When I called Lonestar in 2020 I was told they are wholesale only and directed me to Muskegon Brake as a retail vendor.
One caliper was sent back three times for leaks (DOT 3), each time from a different piston
! I had to send it to Muskegon (Jeff IIRC) who sent it to TX and Lonestar would send it directly back to me.
Since Corvette calipers are done with O-ring seals (not available for 2.125 Chevelle bores) I wouldn't anticipate problems. - Bill W