what to use to plug holes when removing rail

[strum]

I removed the picatinny rail from my new M3020 Stoger for a Sumtoy FF3 mount thats ordered.
  That will leave 2 holes open.  whats the best thing to fill those? set screw? or are there any rubber pluges i can get? 
 would these be #8-40 ?

Edit: my local gun store had some but none that matched.  He gave me an assortmenet of what he had in his tray. in there was a plastic plug which i think looks the best but only one. wonder where i can find those?

[Gooserbat]

You can buy filler screws if you know the thread pitch.  Call the gun manufacturer.

[SumToy]

They make a plug for them.   Now other than just not liking the way it looks it not hurt a thing to have them open. 

[strum]

Thanks William. I did find some Filler screws that work but He also had (only one) plastic plug that to me look the best. I'd like to find some more of those.  And your right about leaving them open. it's just me being OCD i guess.