Howdy,
Sounds like you got yourself a deal-deal on that trimmer. The fuel line problem is characteristic. The Japanese seem to refuse to believe our gas is really that Bad!
The top handle saw was designed for bucket pro use. It came out a might heavy, but very durable, possibly as a result. It is a low end torguey saw due to having a reed valve engine, unusual these days.
The mount on the little Shindaiwa saws is the same as the Poulan small saw series, if memory serves me right. In any event, it is a very common mount, and professional solid bars are available as the Windsor MiniPro. Otherwise laminated cheapies.
Regards,
Walt Galer