While it certainly looks like a RAO, it's lens cell, finder mounts, and focuser is different than the others on CNs and AsrtoMart.
The finder brackets on the others look taller and have a third mounting tab in their center.
ok, good points. i am still bidding but maybe it is an syw ae-106 although the cell should be labelled.?
agreed that there is a third mount screwhole hole/tab perpendicular to the finder bracket on a 20te. this one is lacking that tab. it is, however, a large ladder bracket, whereas the not small 40mm bracket on my r73 is a solid post.
ae106 has a ladder bracket but no tab.
agreed that the cell body is different. the outer flange is deeper on the astromart 20te. same for an ae-106 which uses phillips head screws. here is a 20te
and there is a rounded lip or bulge on the 20te focuser right where it joins the ota which is not present on this scope. the focuser looks more like an ae-106.
i can see rao using a different finder bracket over time, but the changes to focuser and objective are less likely. the phillips screws for collimation could be replacements or indicative of a later build.
looking closely i can see the screw holes for a smaller finder where it would be on an r102, and you can also see white paint under the blue. the guidescope remains a very close match down to the focus wheels. the objective dust cap is a dead ringer for my rao dust caps.
so if not an r102 we are back to a 4" f15 longfellow residing in japan with drawtube style, overall design and proportions very close to an r102 and an unmarked cell just like an r102. the d=108mm also fits nicely with the 1670mm length, which would make a 102mm or 100mm an f16. so an ae-106 sounds attractive.