Folks
To get back to the original question, and I don't know how relevant this info is, I have just taken delivery of a couple of straight, unbiased Tom Morris handles from Control Line Central.
My biased Tom Morris handles weigh in at 100 grammes (3.53 ox) and the unbiased are 93 grammes (3.28 oz).
I suspect that when the specific requirements are understood, other designs could come in at lower weights. For me, the handle must be light and comfortable. Beyond that, the precise details of overall size, line spacing and a couple of other factors become personal preference based on the mechanical leverage of the chosen control system.
Cheers, Geoff