Its a course enough thread It is highly "unlikely" that you have bolloxed the thread (Even with Factoring In the Og-effect Parameters!!!) but I believe I have the correct thread chaser at home
Take a 6mm wood chisel and place on the oil sight glass at about 30 degrees, a good Victorian Sorby or a Japanese laminated chisel should be about right, hit the end of the chisel with a hammer, old adjustable spanner or house brick. Make an incision in the sight glass, and prise out, allow the oil to drain and replace the glass,
If this is just too much hassle then perhaps leave the bike ticking over for a week or so and the oil sight glass may just pop out of its own accord.
I'm following this thread with interest.
Just to find out when Og will need to borrow my bike again while waiting for parts to fix his.
Could you wait until i finish the photorally for this year.