Amp Stand Cone Feet

Not sure if this question belongs in this category or forum, but here goes.  

I have two different Billy Bags amp stands  and the cone feet in each stand have screw threads of slightly different sizes.  


I just purchased two used and identical Billy Bags amp stands that fit my amp better but they came without the cone feet (I knew this when I purchased them).  I thought my feet from the other Billy Bigs stands would transfer to the newly purchased stands easily.  Oops was I wrong.  Only one set of four did and the others have screw threads on the cone feet that are slightly too large.

Anyone know where I would look to purchase Billy Bags aluminum cone feet for an amp stand?  I plan on measuring the thread size early next week to ensure if I find a replacement cone foot set, it will screw in the threads.  

Any suggestions or advice would be greatly appreciated.