Yes, either 1:1:1 or just 1:1 the Elmer T. Lee, or Ridgewood, to the Colonel Lee. Try it first in the glass with Ridgewood, since it is from the same distillery you are simply vatting two house whiskeys and albeit their mash bills are different that doesn't really matter. The extra heft of the Ridgewood (e.g., it has more barley malt than the regular Barton mashbill) will likely "fill out" what is "missing" in the Colonel Lee. At the same time, the super-rich character of the Ridgewood will be reduced, which would not displease some.
The three bourbon approach (one-third each) will create more complexity but since the Elmer Lee introduces a "foreign" bourbon there is more risk of the mixture going awry, as it were.