I know this Thread has some age on it, But I will give it a try.
I have an ISP marked 39, Sn. 88702. No big deal but it appears someone fitted an early 39-2 slide to it. Both frame and slide show the same amount of wear. Was this a common cure during its period of service or common after the gun left the control of ISP? I do know that trans 39-2s were being shipped in early 1970.

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Mike 2796
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