Do you mind me asking which quality bearings you used
@gbb ?
Do you know how many times have you replaced the bearings and at what kind of mileage intervals? And have you swapped the whole BB out for a new one at any point or have just new bearings sufficed so far?
The BB400 was notorious for some, getting as little as 1000 miles before they gave out apparently. Mine managed 1800 miles. I used SKF bearings but I have access to the trade so got a really good price. Most decent bearing outlets will have or get them. I had the bike for probably thousands of miles after and never had to touch them again.
If you know which bearing you need, let me know, I have quite a few, perhaps I have the ones you need....id be happy to let you have them FOC, I'll never use them again, different bike, BB etc now.