Firing pin for a Winchester Model 100
Where can I get one and can it be installed by an above average mechanically inclined laymen.

Nu-line has a Win 100 firing pin service. They do not offer the firing pin by itself.

http://www.nulineguns.com/part_part_273_2_21_64.php

The original ones were recalled, they are a snap to install, II may have access to an original, email me and I will check. Jkob60@msn.com

Thanks for the information and offers but trolling around the interweb I found a phone number and when I called they answered "Winchester".
I told them my wants and they asked for the serial number, checked to see that it had never been in for the recall.
Told me to mail in the old firing pin and they will send me a new pin and 30$ for my trouble.

Here's the info:
Call 800-852-5734 or write them at:
Winchester Firing Pin Recall Notice
PO Box 10
Cottage Hills, IL 62018

Lordy! That recall has been around for decades. I'm surprised that someone has been retained to continue dispensing updated firing pins.