Largest WW1 Zeppelins had about 22 crew-members,Have an interesting idea: How about a small dirigible captain conscripted into a military, to serve as a bomber, an aerial scout, and transport? The ship (boat?) would be an airship equivalent of Illya Muromets, carrying two dozens of passengers maximum or equivalent tonnage of mail, now converted to carry bombs and observatory crews.
Could be interesting to see how he deals with suddenly being placed under a military order and having to bomb people when he would rather carry mails and passengers around, and with his beloved ship increasingly becoming an efficient tool of destruction.
That said, I want to update the introduction to the setting with the latest materials first before writing a story in it.
WW1 German were something like this:
LZ18 17 men
LZ21 17men
LZ39 15 men
Postwar British (R33/34) and American (ZR-1) had a crew of twenty.
As far as Zeppelins used by military go, at least.
Hindenburg was pretty large, and carried 97 passengers, of which 62 died in the crash. It was luxury airliner.
WW1 R-class was 199.49 m (644 ft 8 in) long, and with a volume of 55,210 m3 (1,949,600 cu ft). They three to four tons of bombs and reach speeds of up to 103 km/h (64 mph), powered by six 240 hp (180 kW) Maybach engines.