oil leak from mechanical fuel pump and speedo cable

Hi, can anyone tell me where I can get just the O ring gasket for a mechanical fuel pump for a Mk1 clipper 1.8 carb. I've got an engine oil leak from there.

Also, I've got an oil leak from where the speedo cable connects to the g.box so I need just the gasket for that also.

alteratively can anyone recommend a sealant I can use in the meantime.

Thanks,