Very cool. Thanks for sharing; I don't think we've ever seen the underside for certain before.
I wasn't aware of any auction photos or screenshots that clearly showed the bottom of the Scanner I, but to my chagrin I went back and noticed this when you mentioned it.
There are no photos of the butt end of the TMP Scanner I, so I had to make an assumption that they made it the most natural way (i.e., with two pieces of fractional-inch bar stock). This seemed reasonable given that it looks a pretty hastily thrown together prop in other respects. I carried that assumption into the Scanner II replica and therefore somehow missed this detail. Though I suppose I'm sort of glad; it's a more or less inconsequential detail, and these were already quite a challenge to make with any precision/repeatability rather than just as a one-off. Having to line-bend the bar stock (or, worse, mill it like that) would have been a huge pain, and in up-close in-person inspection would almost certainly not have ended up looking as clean as the design I went with. Mine was already an avowedly "idealized" version of the prop.