When dealing with vintage bicycle restorations, we often run into the need for specialty tools that can be difficult to find, or even to determine what tool is needed. Cassettes and freewheels are one of these issues, as many older manufacturers used their own puller standard that has long since disappeared.
Here's an excellent resource from Park Tool that covers the most common questions, procedures, and tools.

One popular older standard that Park does not cover is the 20mm 12-spline Shimano puller. If you have a pre-1985 Shimano freewheel, it's likely the one you need. Fortunately, we have stock here at HoopRider Parts.

Another common obsolete cassette standard had an outer thread-on cog instead of a lockring. To remove these cassettes, you need two chain whip tools. One to hold the cassette from rotating and the other to un-thread the outer cog. These can be extremely tight after years of self-tightening due to high torque, high gear riding, so good quality tools and some patience will be required.
Many other rare obsolete standards exist as can be seen in this photo.  
Locating some of these and other older designs will require research and accurate measurements. Good luck with your search. And here's a link to the pullers that we currently have at HoopRider Parts.  https://www.hoopriderparts.com/index.aspx?pageid=2289762&chainID=244687&txtQuickSearch=puller