YT6800 Belts

All, I am looking to replace all of the belts on my Yamaha YT6800.  I have the original part numbers...

JE8523550000 YT6800 Mower Deck Belt
JE8524360100 YT6800 PTO Belt 2
JE8462410000 YT6800 PTO Belt 1

I also saw on this board that one of the belts has an equivalent part number of LB67.  However, I am not sure which belt LB67 is.

Are there other substitutions that can be used so I don't have to pay the outrageous prices for the original belts?

Thank you.