LOL - I picked up a 3500A spool for my 3500B reel and found out the HARD way.
I ended up mailing it back to the guy since I was passing thru on a trip.
The handle on the OLD 4500A (barrel style) fits on the Shimano Spheros 8000 and newe style 4500B baitrunners.
When I first got me Spheros, I didn't like the handle and pulled the one off my 4500A BR to see if it was threaded the same and it was.
Spools don't interchange between the BR & Spheros....lol. :P Extra spools were around $25...... ouch!
The handle on the old 3500A baitrunner does NOT interchange w/ the 3500B. Any one need a new 3500A handle??
I've never sent a reel back to Shimano before, but folks say they take care of them.
Don't get me wrong, Mr Sandman - I LOVE using high end stuff but I know I can use low end gear and enjoy fishing just as well.