[name_f]Love[/name_f] [name_m]Gustav[/name_m] [name_m]Rupert[/name_m] and sibling of [name_m]Frederick[/name_m] would fit but [name_u]Antoine[/name_u] [name_m]Frederick[/name_m] would be better.
I think [name_m]Gustav[/name_m] and [name_m]Hugo[/name_m] “[name_u]Gus[/name_u] and [name_m]Huey[/name_m]” sound wonderful together. My second choice would be [name_m]Gustav[/name_m] and [name_m]Arthur[/name_m] “[name_u]Gus[/name_u] and [name_m]Artie[/name_m]”. I do not think of the kid’s tv show when I hear [name_m]Arthur[/name_m]. I do think of [name_m]King[/name_m] [name_m]Arthur[/name_m] but that is a positive.
I honestly can’t stand the nn [name_m]Huey[/name_m]. [name_m]Hugo[/name_m] is an awesome (short!) name; why ruin it? Not to mention the [name_m]Huey[/name_m] [name_m]Long[/name_m] association…
[name_m]Arthur[/name_m] ([name_m]Art[/name_m]/[name_m]Artie[/name_m]) - I like this. I am unfamiliar with any tv show, though. Still, this gives you a fun nn and a nice formal name. And [name_m]Artie[/name_m] sound great with [name_u]Gus[/name_u]!
[name_m]Fredrick[/name_m] ([name_u]Freddie[/name_u]) would also go well with [name_m]Gustav[/name_m]/[name_u]Gus[/name_u].
[name_m]Walter[/name_m] ([name_m]Walt[/name_m]) is just not a name I like the sound of. It still feels very gramps-ish to me.
[name_m]Winston[/name_m] ([name_u]Win[/name_u]) - love, love, love! [name_m]Winston[/name_m] [name_m]Churchill[/name_m] is a fantastic association! He was brilliant, a fantastic writer and historian, and he led the free world through the greatest crisis in modern history.
I [name_f]LOVE[/name_f] [name_m]Gustav[/name_m] “[name_u]Gus[/name_u]” [name_m]Rupert[/name_m]. And I like all of your other names, but my problem is I don’t love any of the nicknames. I love [name_m]Hugo[/name_m] but not [name_m]Huey[/name_m]; [name_u]Freddie[/name_u] is fine; and [name_u]Win[/name_u] is cute but it doesn’t feel substantial enough to stand alone as his everyday name, like [name_u]Gus[/name_u].
I voted for [name_m]Hugo[/name_m] nn “[name_m]Huey[/name_m]”, but I much prefer [name_m]Hugh[/name_m] nn “[name_m]Huey[/name_m]” (especially with [name_u]Gus[/name_u]).