I found a man that I think is the John Brice for whom I am looking in a Boston city directory on Footnote for 1916. The name here is J Munroe Brice, but the address is a match. The residence (at least one of them) is consistent with an address provided for John in an estate settlement in Hancock County, Illinois, in 1915.
The probate settlement indicates John's residence was 24 West Boston, which is one address listed for him here, perhaps a work or office address. The estate settlement only lists him as John Brice, 24 West Boston, MA. There seems little doubt it is the same person.
I really like having access to the city directories at Footnote. I'm going to have to keep researching this Brice to determine what he was doing in Boston and if his middle name really was Munroe.