Thanks for the information, John. Until recently I had only seen the ones with the pipe down the side. Two weeks ago I aquired one that has both hoses going in the base, non electric. Did they make different cylinders for the 77 &amp;amp; 88 series, a different one for the Super series, and yet another style for the triple digits or were they all the same? How many styles would make a complete collection for these series tractors? Also, I think someone posted the Hydra-lectric was brought out around mid-1951. When did they stop using it? Thanks Jim T