Replace or swap your Regal Vice to a pedistal Base configuration. The Long stem found on clamp models are too tall for the best stable pedistal base but with this piece you can make it work.
Alternate between a C-Clamp and a pedestal just by changing the stem, which is easily done with the allen wrench provided with each vise. The short stem here is best for a pedestal.
*Stem length is 6" to the bend
Regal Short Stem and Swivel for Pedestal - item number: SSP+SW