I can't help you with info specific to your 364, but I'm guessing your glow plug system is much the same as a lot of others. My Kubotas have that type of system. The glow plug indicator is merely a resister that glows as it gets hot, corresponding to the temperature of the glow plug, itself. You might try Kubota, as a source for a replacement, I see them listed on ebay, occasionally. Yes, you can bench test your glow plugs, just apply 12 volts, for a few seconds, they should get noticably warmer, just don't apply 12 volts for very long.
And, by the way, welcome to the forum!