Livid , I suspect the VW-18 is a 18 inch actuator ( probably not sold now but was marketed recently) here is info on the others that i found.
the v76-5 is sold on ebay by the von wiese folks or at their website ( the others are sold at their website)
V 76-5 $269.99 from Von Weise
Is a Heavy Duty 24" 48 pulse count 600 lb load 7.5 - 10' Suggested mesh dish size counts per revolution = 8
Solar Panel/Satellite DC Actuator with Telescoping Tube Assembly. 24-36 VDC 1/15 HP Bidirectional Permanent Magnet Input Motor. 600 lbs. Full Load Thrust. Linear Velocity at Full Load Thrust 6.8 – 11.0 in/min. with 24 Inch Linear Stroke. Reed Switch Feedback Control. Limit Switches for overall stoke control. Enclosure Totally Enclosed Non-Ventilated. 19:1 Gearbox Ratio
V 76-10 $269.99
Is Heavy Duty 18" Actuator Arm 600 lb load 6' - 7.5 Suggested mesh dish size counts per revolution = 8
Solar Panel/Satellite DC Actuator with Telescoping Tube Assembly. 24-36 VDC 1/15 HP Bidirectional Permanent Magnet Input Motor. 600 lbs. Full Load Thrust. Linear Velocity at Full Load Thrust 6.8 – 11.0 in/min with 18 Inch Linear Stroke. Reed Switch Feedback Control. Limit Switches for Overall Stoke Control. Enclosure Totally Enclosed Non-Ventilated. 19:1 Gearbox Ratio $269.99
VW-24 $229.99
Solar Panel/Satellite DC Actuator with Telescoping Tube Assembly. 36 VDC 1/15 HP Bidirectional Permanent Magnet Input Motor. 300 lbs. Full Load Thrust. Linear Velocity at Full Load Thrust 11.0 in/min with 24 Inch Linear Stroke. Reed Switch Feedback Control. Limit Switches for Overall Stoke Control. Enclosure Totally Enclosed Non-Ventilated. 28:1 Gearbox Ratio counts per revolution = 7.6258
VW-24LC $229.99
Solar Panel/Satellite DC Actuator with Telescoping Tube Assembly. 36 VDC 1/15 HP Bidirectional Permanent Magnet Input Motor. 300 lbs. Full Load Thrust. Linear Velocity at Full Load Thrust 11.0 in/min with 24 Inch Linear Stroke. Reed Switch Feedback Control. Limit Switches for Overall Stoke Control. Enclosure Totally Enclosed Non-Ventilated. 28:1 Gearbox Ratio counts per revolution = 3.813 ( not a good count ratio for a big dish in my opinion)