Bell’s translation:

When I had finally discovered the meaning of such terms and concepts as Barackenbestandteillager, Zusatzkostenberechnungsschein, Bagatellreparaturwerkstätte, Menagetransportkolonne, Küchenbeschwerdeorgane, Reinlichkeitsreihenuntersuchung and Entwesungsübersiedlung…

Leaving the words in German is certainly a valid strategy. A German reading the text in German might, as Scheithauer writes, pass over the terms too quickly. For a German-speaking reader of the English, the general meaning of the terms can be gathered. This would not be the case for other readers. It is likely that this approach was discussed with Sebald.