happy holiday to you then sir! only thing is you might want to put some sealant around the rubber portion and on the plastic cap when you fit the two pieces together (its a snug fit though and really shouldn't be going anywhere unless you try to remove it!)
If the "sample plug" I ordered fits better, I'll let you know! The size of the hole is 1 1/8 or 28mm I believe, I was having trouble finding a plug that size, and I stumbled onto that company's website last night when doing a google search.
For 99% of us, reusing the existing hardware works perfect, however, for the 1% of us that have OCD, I hope that my sample plug will provide the ultimate clean solution
Hell, if I was you I would just order a sample from them too (it's free)