I actually have one of those, as well as a Realistic cardioid dynamic model 33-1071.....the stereo "electret" (yes, that's actually the way it's spelled on the mic)I have found to be pretty much useless....the other one, the "cardioid", actually sounds pretty good, if you're really close in, or using it for a guitar/amp mic......
I bought the "cardioid" in about 1972, I think...the stereo thingy I found in one of my dad's empty rent houses about 1985 or so.....I thought maybe the stereo one would be neat to use with a band I was playing with, placing it close to the drums.....it was useless.....
I'm pretty much mic poor.....although I like my Carvin CM 68...it's specs are right in the middle of SM 57's and 58's, which makes it a good workhorse for home recording only.....
The radio shack people I've talked to around here know nothing about the Realistic brand they used to carry, so I went to Radshak's website, and Realistic isn't mentioned there either....
I had a Realistic turntable (looked like an AR) and amp when I was in college, as well as some heavy speakers....all good stuff, nothing like Radshak has now, so maybe the company that made this stuff won't let them talk about it anymore....gibs