I believe the shift pattern on some of the older Clark transmissions used "L" to indicate granny gear. It's possible that the 1-4 gears are all synchronized, with L and R being a straight cut spur gear that serves as both ratios, with an idler for reverse. That's how the SM-420 does it. 2nd. gear in a 420 can be selected without coming to a full stop, which gives a driver more options than the 3 speed does.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
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