Thats really interesting! At the very least it would surely appreciate in value since it is a prototype and probably next to impossible to find one available to purchase. I notice it has 2 knobs for SAT and Disc, which was combined into whats called the dual control on the final MXT Pro. Another intriguing difference is the PROG button. I assume this toggles between C/J, Relic & Prospecting modes. Also, it appears to be missing the toggle switch on the right side as well, replaced by a push button below the screen called 'STAT/TRAC MODE'. I wonder if it is missing the SALT function of the ground balance? Thanks for posting the pics! You should not let it go too cheaply until you know if its valuable.