Komet Trailer Rebuild

I'm doing a partial rebuild on a 30 year old Komet trailer. I want to replace the large rubber gasket on the top of the tail gate, the Tee handle in the tail gate and the Tee handle on the front hatch. All this stuff has metric dimensions. I will replace parts with English dimensions only if there is no other option. Price quote from the German factory took my breath away ($230 USD). Does anyone know of a US supplier of generic versions of these parts?

Thanks,

Bob