Sweet set-up! With the triple chain wheel, you got some deal for $50! Rear rack included? In most markets, that's a $200++ bike "in season". The Ishiwata 022 tubing is just fine, that's not the issue for you with that bike . Those 27" x 1" Rigida rims are not very strong at all. At 300 pounds, you will pretzel them in no time. You might have better luck with older Ukai or Araya alloy rims. If I was you, I might just hold onto it as is...if it the frame is the right size that is. Start doing 30+ mile rides, and you might be down to 225 in no time. I would probably still change the wheels (holding onto the old ones for posterity), since IMHO those Rigida rims aren't seriously meant for anybody over 180 pounds. Nice bike! Really super amazingly low price!

Old Fletch must have made the guy "an offer he couldn't refuse"