A frame can work for this but you only see one side and becomes two dimensional. I like open display having three dimensions however the choice is yours and it will be great to see the results. I would remove the recent corrosion then coat the sword in a rust stabilizer that tends to darken the iron. 
It makes for a pleasing finish. Iron and steel were valuable and I can only imagine it's rare to find a damaged sword.
		 
		
		
		
		
		
		
		
	 |