99F in .308 with unclear lever boss code?

[bczrx]

I have just picked up a 99F in .308 with a serial number of 943,xxx [not coy: just don't remember the last 3 digits]. It has a lever boss code that looks like a circle with a 1 7 I or 1 7 J in it. I can't tell which of the last letters it is, or even if I am reading it right side up. The bottom 1/3 of the circle is missing, as the person stamping it held the punch at too much of an angle.

I am thinking it has to be an I or a J letter, but thought I'd ask to see if people here can give me any more guidance with the date based on serial number.

It has the lever-mounted safety, with a brass rotary magazine and number indicators.

Any thoughts about year? And why.

Thanks.

[Mad Dog]

943XXX would be an I for 1957.

[bczrx]

943XXX would be an I for 1957.

Thanks for that. I wasn't quite clear, and there isn't enough to see a hint of a lower line curving up.