I have a very rare raleigh team issue 753 dyna tech , what I wanted to know is , was the team bikes welded at the joints , as my one looks like they are , all the tube diameters correspond with another 753 , even with the seat pin removed , if you put your finger inside you can feel no joints ,and there is also a small hole in side where the top tube meets normal frames have ,to allow gas to escape when being brazed ,I know they say dyna techs were bonded at the joints , but were these very rare few team issue ones welded for strength ?