NOOO!! Test it first. Oktoberfest/Marzen's usually take around 4-6 months anyways.. That is, if you do it the right way instead of rushing it (I've got one I pump out in 2 months). As long as you've kept the temps good, or stable, I'd say give it a go. Taste it. The only thing I'd be concerned about is the fact that it's been sitting on the same yeast for 8 months. Doesn't hurt to try it though.