The diagram above comes from Patent # US4016836, titled “Hydride fuel systems”, filed September 8, 1975. The patent covers supplying hydrogen gas to a combustion unit which includes a mixing unit for mixing hydrogen gas with air for introduction into the combustion unit, and an exhaust manifold for carrying exhaust gases from the combustion unit to heat the hydride material in the container and cause the hydride material to release hydrogen gas.
There is a old documentary video about this system published on this Roger Billings hydrogen technology page that is very illustrative of the advantages of hydrides (see last video link titled “Metal Hydrides”). It includes a tests showing charged hydride tanks in a fire and being shot with a military rifle.
The illustrations of Roger Billings’ 1991 fuel cell car show a similar system used for the hydrogen storage. This patent may give clues about the implementation.
Roger Billings - Hydrogen 