Pretty much everything I did is covered in the first two pages of the this thread. I made a template from a real rallye dash frame, used it to make my initial cuts to the dash with a set of tin snips making sure to leave some extra, and then just did a TON of fitting and trimming. It took forever. And you need to be able to weld or somehow attach the mounting tabs for the new dash, because obviously after you cut everything to fit the rally dash there won't be any mounting tabs.
Restoring the bezel is just patience. Lots of sanding with 220 grit or finer to remove all the imperfections, then cleaning up with alcohol and painting. I used Plast-Aid to do the plastic repairs, it worked pretty well and you can get it on eBay or at pool/spa supply stores. I really didn't do anything to the gauges, just cleaned them up. I did buy several rallye dash's though, so I picked the best set of gauges out of the few that I had.
As I mentioned already at the end of my little how-to, I wouldn't cut another standard dash frame up to fit a rallye dash. The rallye dash frames are easy enough to find, and not really all that expensive. If for some reason I HAD to do it again, I would remove the dash frame completely from the car. Working around everything under the dash is just a pain.