Chainsaw Repair

It doesn't have the keyway or the steel center in the aluminum cast flywheel, just a raised aluminum boss where the keyway should be.
My question is: Has the manufacturer modified the flywheel in production? The date on the old one is "08" the new one is "12".
Thanks

Crank key is molded into the flywheel.  Yep modifed in production and coils are different too.  Was  lookin @  the cranks coils yesterday they will not interchange much to my dismay.  Cut remember the NOS 165 w/bad crank brgs i think the coil is bad too.  That's why I was looking @ the cranks/coils.  Was going to try one off a 962, 956, CS56 those are project saws.
Shep