Chamorros shopping in Manila has been a long tradition on Guam, at least since the early 1900s. In the 1800s, some Chamorros did venture off to Manila for travel, study or commerce, but the scale wasn't large as the Marianas did not have much of a market economy back then.
Sometimes, after a typhoon or drought, for example, relief goods would come to Guam from Manila during Spanish times.
But when both Guam and the Philippines were under American rule at the same time, travel between Guam and Manila was very possible for those Chamorros who had the money to pay the fare.
Jose M. Flores, better-known-as "Josen Anga," was a successful businessman on Guam who kept up frequent commercial contacts with Manila to meet the growing demands on Guam as more Chamorros earned salaries from government and the nascent private sector.
You'll see in his advertisement in the Guam Recorder that many of his wares came from Manila.
Josen Anga's store in pre-war Hagåtña
In the district of San Ignacio