Can I fix my fuel distributor? It has no pressure to 1 cyl.

After looking and replacing everything from vaccum lines to additional air valves in my fuel system to correct a rough idle/miss, Stevebfl reccommended that I loosen each line coming from my fuel distributor one at a time to see if I had a flow problem. Steves "the man", On my last line to loosen to Cyl. #5 no fuel coming out at all. Now what are my options? Can I fix this? If I need a new one, where is the most reasonable place? Also, mine is the black iron type. If I need a new one, do I need to replace my old one with the newer alloy type and what modiffications changes should I have to make? Does it just bolt on? HELP....my wife wants to want to drive her SL this summer.