After multiple teasers, I've been waiting for this video to drop on the Stihl 028. Interestingly, the story behind the saw is similar, that the owner wanted it running again for sentimental reasons.
In this case, it turned out to have a leaking crank seal and general old age on various components. I got lucky with mine, most replacement parts were for perished rubber parts, a new plug and filter. I also requested a new bar and chain, but mostly for cosmetics.
While it's much heavier, I can't help feeling my 028 AV Super runs stronger than my new MS 271. Some of that would be down to the 271 still running in, but I also find the 028 is better balanced. This makes sense when you take the overall construction into account.
The older saws, and the current pro level Stihl's, have a full metal case. The case is split in two and houses the crankshaft and connecting rod, as well as the oil tank, and sometimes the fuel tank. A cylinder and piston then bolt down to the case.
Modern Stihl saws, at least the homeowner and landowner versions, are very different. The case of the saw is plastic and is basically a sled for the contained power unit. The sled includes the oil and fuel tanks, rather than being cast with the lower part of the engine. The engines themselves can be removed as a single assembly from the sled, rather than having to disassemble the whole saw.
Which is better? I'm not sure to be honest. The full metal case would be more durable in professional use, but the plastic case seems to be a more logical layout and offers lighter weight.