It looks like the CAD2 R200 was first produced in 1997. The dropouts most likely will accommodate a 130mm even though the R200 has a 7 speed cassette. Your first step is to take out the rear wheel and measure the distance between the dropouts.
Whether or not to actually completely rebuild and upgrade the bike is another story. It all depends on how much you like the bike and how it handles. You've owned the bike long enough to know how well it dives into corners or handles rough roads, or climbs. If you really like the build and geometry, then rebuild and upgrade. If it is more of, "Well, I've already got a frame...", then you might want to re-consider since parts are at a premium due to the pandemic.
John