Availibility of unique parts used on some bikes only for a few years is becoming more of a problem as bike makers innovate and experiment more. You can't blame Cannondale for a vendor going out of business, and your problem is minor compared to folks who can't source a headset, seatpost, rear shock, or any of a number of parts whose makers, or dimensions didn't survive a long tome.
If this were a fairly recent vintage bike, I'd be sympathetic, but as it's a restoration, you have to accept that sourcing, subbing or making replacement parts is part of the game.
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