1947 Ithaca 37 question

[deadman]

So I bought this shotgun a couple years ago and recently decided to do a bit of work to it. One thing it needs is a bead sight. My question is what thread is an original (era-correct) bead? I could put whatever on it but I want to do it properly.

Anyone up on the earlier Ithacas? Any help is appreciated.

 

[mbk]

6/48. Although I've read that some military and police models used a 4/40

 

[deadman]

Thanks. I ordered a few things from Numrich for it, including a supposedly original style bead. Going to wait til it arrives to check it out, it's been this long so a couple extra weeks won't really matter.