a) Disambiguating Gemini:
Castor is on the side of Capella; Pollux is on the side of Procyon. Easy, no? Capella's the main star in Auriga, the Charioteer, that's way up high and we haven't really gotten to yet. Procyon's in the Little Dog, which looks even less like a dog than the Big Dog. (But both look way more like dogs than The Hunting Dogs look like a whole group of them, but that's another season's constellations.)
[I really shouldn't do my observations and attempts at astrophotography (cursèd low batteries) without shoes on, though. Woo for Alphard in Hydra, though. Next step: using the winter hexagon to locate things outside of the winter hexagon!]
b) My 'Complete Saki' lies, unfortunately.
Ah well. One can't have everything, even in massive omnibus editions. "A Shot in the Dark" and the Clovis story are about the only semi-spectacular ones, in that order.