Thank you ARH, that's much appreciated - and makes it all add-up. :-)
If anyone is interested in what you need to drill out the pilot jet (since getting other pilot jets for this carb seems impossible), I did it with:
These drill bits
held in
this pin vice
The drill bits are so miniscule that the pin vice is essential. I have done a few now with no problems - just turn the drill bit a tiny amount and pull back gently; rinse and repeat. It's soon done, even with minimal force.
Also, if you bought one of the cheap rebuild kits that I linked to above you already have a spare pilot jet in-hand, should things go awry.
__________________
If you have to grind your welds to make them look good, you are a grinder, not a welder... I'm a grinder!