There are a number of manifold options that could be adapted to replace your original part. Count how many 'branches' you need, then add one for a spare. If your plumbing is flexible and long enough it shouldn't be that tough a job to put in a new manifold. Just be sure to label all lines before dismantling the old one! I had one valve on mine start to leak, I was able to swap the line to a spare tap and seal off the leaking one.
Bob & Donna
'98 Gulf Stream Sun Voyager DP being pushed by a '00 Beetle TDI