This is 12mm. Hose size is not Banjo size.
I miss-spoke earlier. Measure the
Banjo OD with a wrench, not the Cap Nut.
I would be surprised if a 78SC still used 10's.
Once known, ask Pelican sales for the correct one. They are very helpful and will find one for you.
I have both if needed, but first ask our host.
Len