Waterpump job is pretty straigh forward for a skilled enthutiast. Did mine a few weeks ago, from a few DIYs on here as guidance. I have never used a Bentley manual or such, just info on here and have performed alot of maintenance type items.
My pump had 122K and looked and bearings felt great. Yours is probably fine too, but for the cheap cost of replacement (DIY) it is good insurance.
Get the OEM metal propeller pump. The Graf unit has spot welds as opposed to the OEM with full lenght blade welds.
Not sure about the copper washer, however there should be 2 small orings on the bottom and a large oring on the top..