AFAIK the Victa Tornado is just Victa's version of the 25.4 cc full crank trimmer that is sold by all the usual suspects (Pope, GMC, Sanli, Aldi/Gardenline, Parklander, and others). I have a couple of them, and like them: the best-idling, easiest priming and starting, and generally least troublesome trimmers I've found so far. That doesn't mean they'll be durable of course - I think the base engine is sound, but there are obvious design defects in other areas. Aldi sold them new for $70 full-retail. You don't get Echo quality for that kind of money.
The drive shaft on the straight shaft trimmers tends to be aluminium with a spline on each end. (Expensive trimmers have, or used to have, steel shafts instead of aluminium, and this is very desirable if you are going to use blades rather than only use line). To extend the shaft I think you are going to need a female-to-female splined joining piece. It would seem you will also need to extend by exactly the length of a standard shaft, since it is extremely difficult to cut your own spline.
