me too. and a bad knee.. and at 77 I can't hear thunder....so I gave my 314-8 to my son - I couldn't handle the lift anymore - and bought a 516 with an electric lift ( so easy ! )... I believe they call these the golden years ,,
yeah, me too...It looks like to me that you could use an industrial type limit switch that uses a whisker ( or roller ) and strap the switch to the front axle and use the whisker to limit the up travel of the snowplow bar...just interupt the voltage going to the winch " up " wire for up limit travel only.. I am assuming that it is a 3 wire system - common and dc+ and dc-, using the frame for common...If , for instance, the dc+ was the up wire, and you broke it with a switch, you would still have common and dc- to bring it down..
lots of them on this page : https://www.amazon.com/s/ref=nb_sb_ss_i_3_9?url=search-alias%3Dindustrial&field-keywords=limit+switch+lever&sprefix=limit+swi%2Cindustrial%2C161&crid=1LD30RWZJDWF8 have to be waterproof of course...I'm sure you could rig up a clamp type arrangement to secure it to the axle..you shouldn't need to reverse....just stop the up travel by interupting the voltage to the motor. You did a really neat job on that...and I'm thinking you could even mount the switch on the bottom front of the vertical piece and let the rise of the plow break the connection with a roller switch...my what am I missing?