Commandos with faulty frame

Well I've been told that even with Norton's many factory produced faults-set backs of early Commando era they couldn't make enough of em to supply demand so main thing that knocked them down was govt socialist intervention experiment 'coopertive' that hung them with the rest of the drownding brands. Still the Combat recalls for series of errors dragged their reserves down in their peak that they never seemed to recover from till the end or cycles and just air craft engines left. Who could afford a Commander but the govt buyers. Sort of like Indian that geared up for govt only then govt moved on.

I'm rebuilding a 68 and was concerned about the frame. When I cleaned off the paint and inspected the "suspect" areas with a 10x magnifying glass it all looked good. I then did a crack test with a dye penetrant kit "just for fun" and found that the R/H down tube was cracked about 3/4 of the way around. The crack was very tight and almost impossible to see with the naked eye. The L/h was ok???

After finding the crack I decided to fit a 1" tube under the back bone like the later frames.

Moto for this story.... If you are going to run a "widow maker" it would be worth getting it crack tested.
The problem is what happens if it starts to crack after it has been checked...