Hello Alex,
CMK market a range of components under their Maritime line to make up a 1/72 scale dry dock suitable for Revells Type VII or IX U-Boats. They range from dock wall components, to stairs to buildings and cranes. Checkout this link
http://www.cmkkits.com/en/ships/index.php?fSort=3&fSeries=0&fScale=15&fNationality=0&fEra=0&fMaker=0Unfortunately they are not cheap and it requires a bit of work to determine how many of each component you need to make a complete dry dock. Also it is hard to find stockists. Besides the CMK's website try Hannants.co.uk. I also had some success with Sprue Bros in the US.
Unfortuantely there is no master plan on how to put it all together. Just the individual instructions sheet with each part. I have also yet to see a completed dry dock. I would be very interested if anyone who can help here.
Good Luck. Burkes