Hallo Graham
In passing, as it were (checking to see what I might have overlooked), I notice no-one has taken you up on knots. Tut-tut, everyone (including me). I'm surprised Tony hasn't had anything to say.
I agree with you about the buntline hitch, and I like its square rig origins and connotations. I don't know the other two and, in one of the spare moments I never seem to have these days, I'll give them a try.
I don't know whether the constrictor knot is 'obscure' (I haven't looked, but I'm sure Animated Knots cover it). I use it sometimes. When you look at its structure, its elegant simplicity is astonishing, and it's the only knot I know which really can't be untied. Don't believe it? - I challenge you!
To one and all, Happy (and safe) Sailing in 2018.