Excelent background post on a bicycle company that I have recently been introduced to. I am currently in the process of restoring a Sport DLX with the Infinity tubing, and a co-worker recently picked up an Ironman Expert frame with Tange #1 and a 105 headset. He's putting an 8speed 105 group on it after repainting the frame and purchasing new wheels, brakes and everything else for the frame. I suspect when he gets done the bike will weigh in slightly heavier than the original has his stem, bars and crankset are older heavier models than what probably came on the bike. As for me, I'm going the other direction and putting a 7speed freewheel, early 90's era Shimano 105 group with friction downtube shifters, and modern dual pivot brakes.
Happy riding to all other Centurian owners near and far.