Sorry, but I haven't been really keeping up with this thread as I should be.
Not having the marker in my possession sought of detracts my attention from it a bit. Though I do check on occasion.
Enough to notice that there are some of you here that have achieved some considerable strides at getting the Thumper to where it should have been before its release.
Now... A bit more about this Gen. lV piston please? These are actually available?