And it is fair enough for an OEM to not supply the parts for free forever. There is a Compliance Date on Bulletins for a reason. Just because a machine is not being flown, that is no excuse for not keeping up to date with Mandatory Bulletins, especially when the OEM will supply the parts for FREE if you order them within the Compliance timeline.
Should be a no brainer and yet there are STILL people out there who can't figure it out.
Oh, and you can ask for an extension to a Mandatory Bulletin. I've had to do it many times when I worked for a 139 operator who couldn't get Mandatory BT's done before Compliance ran out!