Gentlemen,Here is the thing, I have 5513 case from Joshua (latest) and 1680 from PT - pure-time. Josh's 5513 is a bigger case, with fatter lugs, CGs and overall it is a bigger fatter case. Does this mean that the case for 5513 is originally bigger than 1680 or I am just better of using 1680 case from PT to build 5513 and save myself a lot of time grinding and trimming the metal?Interestingly enough, Josh's 1680 case is also thinner than his 5513 but is a bit fatter than PT's 1680.On another point, my 1680 case from PT did not have enough thread - metal to install Athaya tube! so go figure which one to order in the future. Thank you.Hagan