A
Archive4
Guest
You could try hereSadly, it's not 76mm, it's 114.3mm (4.5 inch).
One thing I wanted was to have a "sleeve" for a 4.5 inch pole, so I could join two poles together to raise the height if needed, but not something I could find here
Circle Jerk welded pipe
You might find something you could use. If you cannot find it elsewhere may be worth a call to see if they have an off cut from a 120 or 125 you could use?
Edit. Ignore the link name, not my fault!