The stabs that the breakers plug onto are generally aluminum, and when poor connections occur, they heat up alot. You can easily see what brand breakers they are and get new ones at Lowes, Home Depot, etc. For about $4 each. The problem is finding a power panel or at least the bus bar to replace the old one, which you say is burned. A RV salvage yard might be a good choice.
Bestconverter.com is familiar with power panels and may also be able to help you identify it and locate parts.
Indeed, connections need to all be tightened about once a year to prevent this.
Charles
'03 Ram 2500 CTD, 5.9HO six speed, PacBrake Exh Brake, std cab, long bed, Leer top and 2008 Bigfoot 25B21RB.. previously (both gone) 2008 Thor/Dutchman Freedom Spirit 180 & 2007 Winnebago View 23H Motorhome.