The serial number most likely consists of two letters and six numbers. It's very unusual to find a Spartan in a cabinet, it's usually a 99 with gold decals and a singer lamp. The spartan is of course exactly like a 99, but it's stripped down to the bare essentials. A cabinet is on the more expensive side, that's why I found it an unusual combination. A lamp can be fitted and often was.
You might have to spend a bit of time to get it running smoothly; in other words, detecting oil points, oil, runnig the machine and more oil. To clean under the bobbin case slide the bobbin cover completely off, then lift the lever slighly up and towards you. It will release the bobbin case. The only warning is to not mess with the screw on the lever, it will make all parts slide around, and you likely end up with tension problems. You don't need to to clean and oil, but if you have to for some reason (rust or serious amounts of grime), there are a few blog posts on it, as well as the sevice manual. A clean and well oiled Spartan should stitch perfectly and run smoothly.