Is there a linear DC ESC out there?

[Southgate ll]

My crane project, (in construction equipment) has one function that will not work with a standard reversible ESC. The slewing mechanism (rotation of upper unit) is driven by 2 small gearheads with coreless motors. They have no clue what to do with s standard ESC output. They need "filtered" linear DC.

I made an effective but bulky device from a model railroad MRC transistorized power pack, that uses a servo to turn the potentiometer from the MRC, to arrive at a linear DC control for those motors (powered off the upper unit battery pack) but I would rather just have a clean simple ESC if there is one that can do the job. Anyone know of anything? Dan