Today is the day... National Bookmobile Day (NBD... do librarians have to always use acronyms) anyway, check @yourlibrary on facespace to find any posted events in your area today.
International Harvester produced a stock bookmobile in 1960 based on their Metro Van (as above, I want one of those vans...)
International Harvester Company can infact be credited with the very first motorized bookmobile; a converted IHC wagon. This "book wagon" below traveled through Washington County, Maryland under the supervision of Hagerstown Librarian Miss Mary L. Titcomb [I never heard of Miss Titcomb before doing these last posts... she seems quite a force -ed.]
In March of 1912 an IHC Autobuggy with body by Thomas White was delivered by the International Harvester Company. It had a specially constructed top with shelves for 300 books and storage room for four deposit station cases.
-via Western Maryland's Historical Library