Hi Greg,
I am a little bit surprised that I am the first Pole to answer your question. I have noticed there are some Poles here with a much better knowledge of the WW1 aviation. But, since I am the first one, I will try to add something to the discussion…
Graf von Gluszewski-Kwilecki was a Silesian (as you say in your „Richthofen’s Circus”). Silesia has itself its own interesting history – it was a part of Poland, a part of Germany (and I suppose in the Middle Ages, it may have considered itself a separate state). Therefore German nobleman may have name that sounds Polish. Also there may be a problem with name pronunciation.
I am not a history or linguistics expert but for me Gluszewski-Kwilecki is definitely a Polish name, i.e. derived from the Polish language. Therefore from Polish perspective maybe it should even be written “Głuszewski – Kwilecki” with a “L” with a bar, as Josquin has noticed. The Ł is pronounced like “W” (e.g. in “window”). So it should be pronounced (let’s say: “something like”) GWUSHEVSKY-KVEELETSKY (or even GWOOSHEVSKY-KVEELETSKY).
But… as I have said, the history of Silesia is very interesting so no wonder that someone with a Polish name was a German nobleman

. Since there is no “Ł” in German, I believe Germans would spell it with “L” like GLUSHEVSKY-KVEELETSKY”.
By the way – one of MvR’s relatives was Bolko von Richthofen. I am not an expert on von Richthofen family, neither on German names, but for me Bolko is a form of Polish name “Bolesław” (AFAIK typical for Poland) – another example of interesting history of Silesia, Polish and Germany – German nobleman with Polish name
Best regards,
Wulfryk
(OMG I’m talking to GregVan

himmself! Now I can show my shelf with Osprey books and say “you know, I know the guy, I helped him with his researches”

)