Quote Originally Posted by MattCarey
...the cold head on the E3 takes a set of 4 strait mini-tubes ...
No kidding! I had a 4 X 5 with the same arrangement. Bought
it surplus back in the late fifties. So they still make a straight
multi-tube design. IIRC mine used 5/8 inch tubes.

Your's may use the newer 1/8 pencil thin tubes. Those tubes
are much used now days. What ever the diameter, buy four or
more and plug them in. Shop from Google or maybe eBay. Or ..

Switch to Graded paper and skip the new tubes and filters.
I dropped VC for the higher level of darkroom lighting possible
with Graded paper. Dan