That's a V1 (Version) Silvia, which is a great single boiler/double use machine. Simple/solid workhorse that can give you great espresso, just have to dial in the temperature/pressure with a bit of experimenting. I've had one for a little over 3 yrs and have cranked out around 6,000 doubles with it. Not long ago I replaced quite a few parts in it... not from failure, just preventive maintenance as I use it quite a bit. Get it dialed in with a capable grinder, FRESH coffee, balanced water and some time/effort/patience and it will return the favor in spades.
Will likely benefit from a descale process as well as backflushing. I do highly recommend not using the stock basket(s) as they are a joke. The updated Rancilio 18 gram basket really brings it to life. Also toss that lame plastic joke of a tamper. You don't need to spend much as I've used a fantastic solid stainless 58.0 mm tamper I got on Amazon for $20.
Have to agree with everything said above by Shadow 745, I would also get the newer model 18G basket. It is a precision part. The Silvia needs to be brought up to temperature which can take 20 minutes or more. You can cycle through the warm-up period by pumping a few ounces three times or so. The Silvia will give you years of service and parts are readily available. Make sure your grinder is up to snuff and "choke off" with a powdery grind so the espresso so barely a drip comes out and then go coarser until you get a properly timed extraction. Some of the newer digital machines can produce amazing espresso for a few months... until they fail. The Silvia keeps on ticking when well-loved.
Nice machine. Also agree with Shadow745 and Franklin. Those machines run about $740 new. And they have a loyal following. Get it all cleaned up as recommended and you should be in business.
I have had a Silvia v1 together with a Rocky grinder for many many years. I love it. You have stated that you have the Rocky grinder, which is perfect. Once you get the grind sorted out, you are home free. My only addition was a PID. I believe that it adds a lot., but for the first 5 years I didn’t have one so it is not absolutely necessary. Just replace the head gasket 1 or so times per year and de scale it as needed based on the water in your area. One issue that you do need to be aware of.... The v1 takes the SOFT head gasket, all of the others take the hard one. Be smart, get the soft one, the hard ones are almost impossible to install in the V1.