Blue Book of Gun Values, proofhouse.com
Click the link.
Any auto parts store.
It's just a chart that you will find at most parts stores, that shows you a cross reference, of different brand name filters for that specific car
Here is one onlinehttp://www.wixfilters.com/filterlookup/index.asp
Go to Baldwin filters and enter data requested
You can find a spark plug cross-reference chart on various automotive websites, such as those of spark plug manufacturers like NGK, Bosch, or ACDelco. Additionally, online auto parts retailers like AutoZone or O'Reilly Auto Parts often provide cross-reference tools. Local auto parts stores may also have printed charts or provide assistance in finding the right spark plug for your vehicle.
My cross reference list indicates that this is a Savage 59. If your local gunsmith can't find the parts, you can check with www.e-gunparts.com
Try e-gunparts.com for parts and Proofhouse.com has a cross reference chart that may help.
You can find the Kreg screw chart PDF for reference on the official Kreg website or by searching for it on a search engine like Google.
I can't find a cross-reference for that number, but Eastern Arms was a trade name used by Sears Roebuck. Most of the shotguns were made by Stevens/Savage.
cross by HF6351 FLEETGARD FILTER
You can find a cross reference to this number at Fluitek in the related link.