A couple-few comments to add:
1. The Gunk and Napa stuff are identical to one another.
2. On these early Carbs you have to be careful not to forget them for months. A longer soak can cause more harm than help.
3. For exterior/cosmetic purposes, a ride on the Wire Wheel is preferable to bead-blasting.
4. On ANY antique part it is preferable to start with the most benign process, such as Bill's TSP solution. If it doesn't work you'll still have the part!
5. Adding to the TSP I suggest the following:
a. Use Distilled or demineralized water.
b. A couple of drops of Dawn do well to keep whatever oily substances you may be removing under control. This aids in removing the part from its Bath.
c. Arm&Hammer 'Super Washing Soda' is a a great additive to the TSP Solution. (See also 'electrolytic rust removal'.) Works well on your laundry too!
6. Kerosene and/or Diesel Fuel do quite well at dissolving the gasoline varnish and re-liquefying whatever crystalline substance gas becomes if left long enough to petrify. Unsurprisingly, Kero is the primary ingredient to many --if not most-- of the 'special formula' products sold for this type of task.
7. Lastly, avoid at all costs ANY product containing MEK (methyl-ethyl Ketone).
8. I know this is far more than a few comments and that #7 above is NOT 'lastly' after all. But I opted to know the stuff above rather than learning to count.