Lodola oil line washers

I need to replace the oil line sealing washers on a Lodola. The ones that have come off are the old red fibre type. Have you replaced these and did you use the same type or copper washers instead?

I bought these in the end but in dimensions: 20.1 x 11.8 x 1mm, and they’ve worked perfectly, really helpful seller too, Ebay item number: 131171505364