Seiko Kinetic waterproof crown gasket replacement

[LittleWatchShop]

I have an assortment of gasket/grommets.  Should try one of them or find a genuine Seiko?

I assume that I just cut the old gasket/grommet out...correct?

This watch arrived today from a friend and there was water on the dial.  Not certain the extent of the water damage.  The damage occurred this weekend, so I got it out of the case and started drying it.  Crossing my fingers.

[Waggy]

I think most of the gaskets used on the Seiko stems are the D type ie the cross section is a D shape and not an O shape. So I would measure the length of the gasket as best you can and then get the nearest D gasket you have. I usually try the stem in the case without the movement and see how much resistance/drag(?) I can feel as I slide it in and out. Obviously too much or too little then you need to go down or up a size respectively.

Here is where I got my last batch of O-rings and D-rings from if this is any help - much cheapness  

[LittleWatchShop]

23 minutes ago, Waggy said:

cross section is a D shape

Which one have I drawn correctly?

[Waggy]

The bottom one with the flat on the ID and belly on the OD