Wanted standard Mk2 tx200 tophat

Ok guys been looking at the TX200 parts list & was wondering if any, what the difference in size & weight is between the 3 top hats, TX350H(HP), TX352(.22), TX353(.177) ?

Update I have removed the screw and washer & filled the hole with Chemical Metal. Put an AA seal on & had 12.46 ft/lb, so collapsed a coil on the spring & added a pre-load washer & now have 10.83 ft/lb.

I bought a second hand tx200hc a few months ago, when I stripped it appeared to have a V-Mach kit fitted, it was only running about 9.5ft/lb but was smooth so I went with it. Then when I chrono'd it again the other night it had dropped to just under 8.5ft/lb, so I stripped it down again to investiga...