The hydrogen inside an airship has a mass that is approximately 14 times lower than the mass of air and this difference results in lift.
However the solid material inside an airship including the frame, skin, walkways, gasbag material etc. would also displace air. Would the air that these materials displace also be counted towards lift? I'm not sure.
If the extra displacement is counted towards lift is there any reasonable estimate as to how much space the solid material might fill? 1%, 2%, 5%?
A U Class Zeppelin has an outside volume of approximately 59,000 cubic meters. However if 2% of this volume was solid material that's 1,180 cubic meters of atmosphere displacement or an extra 1,445 Kg of lift. Although not decisive I'm sure that any little bit helps.