It would appear to me that in one of the pics there is a Swarovski spotter with the 2 eyepiece setup next to the bench?
Ive looked thru the regular twin Swaro setups but not the one using just one tube.
Ive also not looked thru Leicas.
I have a set of the older 77 mm Kowas, and have both 20x and 30x wide angle eyepieces for them.
I also had a set of 15x eyepieces made for them from good telescope eyepieces. A bit tricky to do since Kowa uses a bayonet type eyepiece as opposed to a threaded one.
On days with high mirage the 15s are much clearer than the higher powers.
As for seeing small brow points at the longer distances, thats not always an easy thing to do, even with very good optics having large objectives.