Hi John;
Nice set up; it might not be fancy, but it sounds as though it is doing the trick for you. I considered 40's but I remember my experience with my Lotus 907; I used twin Dellorto 40's on it (1970cc double overhead cam etc) and was so sorry that I had not spent my money on the 45's, as I was constrained by the limitation that the 36 choke provides. The 40's were a vast improvement over the Stombergs stranglers that the Federal version 907's came with, but from all accounts I should have spent a few more bucks and got the 45's.
Your delight in the sound and immediate performance of the side draft carbs echos my own on the 907; I would love to replicate that on the 1800.
J DYmond