A 38mm coupler size would be a little too big for what you are looking for:

https://www.discountrocketry.com/mo...ler-p-2299.html

1.515" OD rather than 1.44". If no one makes this size then your best alternative would be to "cut down" the diameter of a slightly larger tube, like the BT-60. Calculate the difference in circumference of the smaller tube and the BT-60 using c = 2 x pi x r ( or d x pi). Mark a vertical strip on the tube equal in width to the difference in circumference and cut it out, trying to cut as straight as possible. An angle tool is very helpful. Use the strip as a glue tab and join the cut ends together. Saw a post on the net a couple of years ago showing this but can't seem to find it now.

Another option is to make your own custom sized spiral or convoluted tubes using kraft paper. However this would entail using a mandrel or tube that is the exact size you need to wrap around, so you would have to construct it or get lucky and find one that's the exact size. Way too complicated.