1985 International 1753 bus clutch plate

[Icebike]

I have a 1985 International school bus Model 1753. Clutch is finally slipping a bit. Anybody know how or where to order the clutch plate?
According to the line setting ticket under the hood it has a T243 5 speed Spicer Trans. On the ticket also I see 13IN Spicer CL Push-Type. Not sure if that is a 13" plate or not.
A few years back I replaced the 6.9L with a 7.3L and did notice it had a ceramic clutch plate.
Any info would help. Thanks.