peerhaps it was a process carried out by Verlichi to prevent the cracking of the frame ( HAZ,heat affected zone) less welding means less heat,just above that incomplete joint, which would have showed in Keith's pic if it was there.
I have said before that IMHO the cracking of the frame tubes is caused by the individual welder, not the design, which explains why some frames go on for ever without cracking and others fail easilly.At lest that is what I have found on the ones that I have repaired (undercut, cold shuts, ovelay etc).This proves the point at least, that quality control at Verlichi and at Moto Laverda was less than perfect.
CLEM