Sorry the test 30 mile cycle was not just as good as it may have been, some times i find it takes a bit of fine tuning to get a bike just right/ Your Lenton looks great and i am sure if it was parked up beside a lot of new expensive bikes yours would be the bike that would get the most admirers.
Just a thought but your saddle looks very far forward? perhaps try and adjust setup a bit? What i usually do is line up BB with another bike i know i like setup on then adjust saddle and bars to a similar setup, know the first really good Wednesday or Friday i can get out i am going to take my Lenton on a club run (Wednesday and Friday are the steady runs) , only my view but Lentons are great bikes not be the fastest, rarest or best looking but just a great classic bike that still turns heads every day.
Quick edit, just a thought but my Lenton is 4 speed? Is your rear hub 4 or 3 speed?