This is what we refer to as "the horned animal clubs" such as Elk, Eagles, Moose, Mason local chapter? Not church associated?

I would start out by looking back to those older 990 filings to see if hall rental was reported as UBTI. You state it is not to a significant degree, but it's not program related (outsiders, not beneficiary members) or was it only to members? Also, did they cater events for their renter (provided services)? Is this one of the buildings with small rental rooms available at low rent for low income members?

(just released that's a lot of question marks)