Maybe through expensive forensic services... but if your old restore points
aren't there anymore, that means they've been overwritten, which means the
portion of the hd they used to occupy is now filled with other data. There
may be fragments still intact here or there, but unless you use extreme
measures, the data is gone.

"Deleted" data can be often be restored with relatively inexpensive tools
(compared to the alternative, doesn't necessarily mean they are cheap), but
once something's been overwritten, you are essentially out of luck.