Oooh, flash, you've got the "retail" Munton packaging rather than the white-label one. I happen to have a pack of that kicking around and it looks like they have 3-year best-befores nowadays but may have been 2 years back then, so I guess the yeast was packed in either October 2011 or October 2012. It's still available, or is a close relative of S-33 and Windsor if you can't find Munton's but are worried about viability and feel the need to be "authentic". 7-8 year dry yeast ought to be OK, if past its best.
I sympathise with the suggestion to just view it as a source of starter material - but heck, just brew it!