Model 640-1 question

[giddyupsut]

I was going through the safe and found a purchase that I had forgotten about. It is a 640-1 SS that is ported. I have found only one reference, in the SCSW to a ported model and it is the "Quadport" Lew Horton order. Mine is not a quad, just a single slotted port along the rib on each side. The ports appear stock....I'm a bit confused?? Any insight would be greatly appreciated.
Info:
S&W 640-1 SS, 2.25bbl ser#CBM98XX

[Broadside]

Do you have the original box for the revolver?

I think if it were stock it would somehow be indicated on the box.

It could very well have been Mag-na-ported at some point. In fact, the distributor may have sent it to Mag-na-port to get it done. So it may have arrived at the dealer with the porting already done.

The SCSW doesn't have everything. I think you may want to make a call to S&W to see what they can tell you.

[giddyupsut]

That's what I figured. Unfortunately I cannot find the box, as I have been transferred and moved several times since the original purchase.
Thanks for the input.

[AZretired]

This is obviously a sign you have way too many guns if you forget you even have them. I wish I had your problem!