Head board on a full-size bed purchased new about 1940. The side rail has a steel latch which fits into a vertical slot on the headboard post and hooks onto two pins which are horizontal through the post in the direction of the width of the bed. The pins and the wood comprising about half the post were ripped out by clumsy attempts to disassemble the bed in 1944. For years, the bed was used with a shop-built box under the rail on that side for support. Try as I might, I have not devised a good plan to repair that area with wood. Preparing for a patch will involve removing even more of the existing wood. And the patch will have to hold the pins which are about 5/16 diameter- I have not measured them.
The Minwax product is polyester-based and I wonder if the bond to the existing wood and the strength of the Minwax filler will equal or exceed that of the original wood. I can fill with JB Weld if necessary which has much greater bonding strength.