How do I join a table in db1 with a table in db2 to produce a resulting
recordset?

use linked tables
FILE->Get external data->linked tables (these are table linked in from
another database

then run you query.

also
see ACCESS for select using jet.  use external database in select statement
...for example

SELECT [predicate] { * | table.* | [table.]field1 [AS alias1] [,
[table.]field2 [AS alias2] [, ...]]}
    FROM tableexpression [, ...] [IN externaldatabase]