There are no pulleys and gears on a traditional push-pull mechanical control system. There are commercial systems like Kobelt and custom systems that sound like what your have, but nothing "off the shelf" like what you describe that doesn't climb into the price realm of electronic controls.
For traditional "off the shelf" push - pull cable systems:
Twin station, dual lever controls, single engine:
either rigged series or parallel: 4 cables
Twin station, single lever controls, single engine:
6 cables, 2 junction boxes, + 1 cable w addl control for station selection
These are the off the shelf current choice by the mainstream manufacturers. The number of components and total friction in the second system totals more equaling more initial cost, more total friction, and by having more components, less reliability.
Please don't take it personally Lou, this is not apples to apples. You have a custom HD control system fabricated by a reputable builder, an off the shelf mechanical control system just isn't in the same ballpark and your system could not be duplicated for less than several boating units.