Mirror re silvering is always painful especially with an older scope, you can start pondering the economics. There is a cheap DIY method that works but the coating doesn't last as long as an over coated al mirror.
http://angelgilding.com/kits-chemicals/pouring-silver.html and then my dodgy home recipe.
http://www.iceinspace.com.au/forum/s...ight=silvering
If it's a good mirror it's worth getting a professional job. Your mirror looks pretty good though from your images, not a lot of coma showing.