SOLR numeric value search with LUKE

SOLR numeric value search with LUKE

While Lucene numeric range search with LUKE exists, it doesn't answer the
question so I have no better idea than ask again. I am using Solr 3.6.2
(the app I work with is not 4.0 compatible) and Luke 3.5 -- not because I
am particularly attracted to Luke but because I can't find anything else.
Is there a better tool to debug Solr indexes?
Here's the field and the value:

I go to the search tab, click the Use XML Parser and then
<BooleanQuery>
<Clause fieldName="is_filter_by" occurs="must">
<NumericRangeQuery type="int" lowerTerm="1" upperTerm="3" />
</Clause>
</BooleanQuery>
No results. It gets parsed to +is_filter_by:[1 TO 3]. I can not find any
documentation on this XML format so I have no idea whether this is correct
or not.
I tried to set the default field to is_filter_by and enter 1 without XML,
still no results.
I tried two clauses. I tried occurs="should".
Reconstruct & edit says: Stored original 1.