Märzen Should be rich, malty and medium to full bodied, but still very drinkable with a nice dry finish. they should not be like a maibock or anything. And unlike the modern straw colored German Festbiers they should be Amber and very malt centered.
Märzen is one of my favorite styles. Especialy the stronger Oktoberfest styles that you lagger all summer. Oh yea Märzen were called Märzen because they were usualy brewed in March to last through the summer since brewing used to be outlawed during the summer months in Bavaria before refrigeration. So they would make some stronger stuff to last untill, you guessed it Oktoberfest in September when brewing could begin again.
I've never had the dundee, but sounds like it's somwhere between the Märzen and the modern Oktoberfiestbier in Germany that's almost pushing on strong German Pilz now. Not sure about the smell. It should smell like you stuck your head in a bin full of Munich malt. The Märzen is a liquid shrine to Malt. Perhaps it skunked? A better representative nationally is Sam Adams Oktoberfest. And Great Lakes Oktoberfest is my go to beer in fall, but you can't get that in Maine I don't think. And this late in the season I'd be wary. They are a seasonal thing.
Basicaly for brewing just get a whole bunch of Vienna and Munich malt and I like Caramunich (60L) to get a nice rich coppery golden color. Mash around 155 or a little cooler to ferment out about 10Plato (40 points) but keep some body without making a bock like liquid bread. I do bittering and some flavor, but hops should be way down on the taste and aroma profile. Just enough to balance and add depth.
The key is think german lagger, not Harvest beer/cookie beer like most of the stuff that rolls out these days come the turning of fall.