re: QSWO Entry Table Repair

One nice thing about hide glue compared to PVA is that you do not have to completely remove it to get a good bond.   New hide glue will adhere to old hide glue which is one reason it is preferred by antique furniture restorers.  Just get as much of the grime that has accumulated in the joint off (DNA or MS may help) and you can often just squirt some more hide glue into the joint to re-secure it as long as the dowels are still tight enough.  You could add some corner braces to strengthen the corner/apron joints  if necessary.  

If it is hide glue but not shellac or lacquer, but it looks like it is not just a basic boiled linseed oil type finish, it may be some sort of varnish made from pine resin as was done before the synthetic resins became used.   If you do not want to strip off the old finish, I would probably just clean it and see if a paste wax will freshen it up enough for your purposes.  I have never tried it but I have read that a dewaxed shellac can be applied over old varnish.  I've used Howards feed and wax to revive really old finishes that I do not want to strip too but it is not my first choice as it can take a while to dry and it does not really replace missing finish.