Nothing really "resto-mod" about it. The seats are hideous and the trunk upholstery isn't much better, but both of those are easily changed. If you replaced the seats with factory stuff and pulled the trunk upholstery and over the top stereo stuff it would look pretty stock with some mild engine performance modifications.
Looks like a bunch of money was spent and it's at a dealer so I'm sure the asking price is probably more than the market value. Based on the upholstery I'd say the restoration was at least 10-15 years ago, but it looks pretty clean. Obviously to know that for sure you'd need to see the actual mechanicals and inspect the work up close.