Using Fuseki to query the union of datasets

[Scott Henninger]

I am attempting to use Fuseki to query the union of a set of datasets.  I am 
using the following configuration to define a TDB dataset named "union-graph" 
and setting tdb:unionDefaultGraph to true to query the union of the datasets.  
However when I query "union-graph" I do not see the triples from the datasets I 
have populated.  How can I configure Fuseki to query the union of datasets?

Thank you
-- Scott

@prefix : <#> .
@prefix fuseki: <http://jena.apache.org/fuseki#> .
@prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .

@prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> .
@prefix tdb: <http://jena.hpl.hp.com/2008/tdb#> .
@prefix ja: <http://jena.hpl.hp.com/2005/11/Assembler#> .

[] rdf:type fuseki:Server ;
    fuseki:services (
    :service1
    ) .

# Custom code.
[] ja:loadClass "com.hp.hpl.jena.tdb.TDB" .

# TDB
tdb:DatasetTDB rdfs:subClassOf ja:RDFDataset .
tdb:GraphTDB rdfs:subClassOf ja:Model .

:service1 rdf:type fuseki:Service ;
    fuseki:name "union-graph" ;
    fuseki:serviceQuery "sparql" ;
    fuseki:dataset :dataset ;
.

:dataset rdf:type ja:RDFDataset ;
    ja:defaultGraph :model_default ;
.

:model_default a ja:InfModel ;
    ja:baseModel :tdbGraph ;
.

:tdbDataset rdf:type tdb:DatasetTDB ;
    tdb:location "DB" ;
    tdb:unionDefaultGraph true ;
.

:tdbGraph rdf:type tdb:GraphTDB ;
    tdb:dataset :tdbDataset ;
.