I never realy liked replacing rope seals. They can be a real pain in the a$$. But I have been sucessfull with every one I put in. The 2 piece rubber seals work as well just make sure you use a little dab of sealant between the 2 halves. I have done several of these as well and only had 1 fail to seal.
Fail rate 0 for rope, 1 for rubber. Close call.

I didn't do it, no one saw me do it, you can't prove anything! "Bart Simpson"