Well if it's any consolation, I am about the same height and weight...
And I think well my 1930's + 45 Harley was about the same size...... (basket case built into a real motorcycle.) But this is under half the weight, gets about 4 X as far per liter and has a 40Kmh higher top speed.
Yes it could do with a bigger tank as in rural Australia a 200 - 250K round trip is a local drive - to the nearest anywhere.
I had much to do with Phil Irving and the Vincents - and they were about the same size only about 20cm lower at the top of the handle bars and all - a very small 1000cc bike with a 150MPH speedo.
My main concern is to make the seat sit up HIGHER and tilted forward, with more cushioning and more springing to hold me up....
But size being what it is, it's SMALL, LIGHT, easy to push - turn off the engine and take it all sorts of places - like on the foot path up one way streets - even with a flat rear tyre.....
And in the really quiet back single lane back roads where people drive like farmers and city drivers hit trees and wild life - in fouth gear it runs quite nicely at 60-70Kmh...