well I'm damn lucky
as 308mm mandrel is perfect for what i need. its only a few mm larger than berthers current skirt but a bit of frilly stuff will make it what i need!
I'm not sure if they have any smaller mandrels than 308. but like i said once it all goes though depending on price of course I will report on the quality.
It should lighten up the overall OTA by a bit but not to the point of OMG this thing is a feather! If anything I am more doing it for the A. looks B. thermal stability.