[Wavytone]

I used to have the big brother to that mount in the early 1980's.

At that time the larger Carton refractor - which I think was a 4" f/13 clone of the Unitron equivalent (though it didn't look half as good) - was usually supplied with 3 x 0.965" eyepieces - 25 and 12mm Kellner, and a 6mm ortho. Fairly sure they were generic unbranded ones which were quite common in the 70's and 80's though probably of the same origin as the circle-V ones, i.e. Vixen Japan.

I would expect similar for that scope. If there was a star diagonal it would have been a 0.965" prism type.

One thing to look at closely is the tripod - the legs on mine were softwood stained brown - lightweight but not particularly strong and easily damaged. I rapidly replaced it with an old Miller tripod which i picked up secondhand.