replacement fuel pump on 230ge

Hi again ive a problem with the fuel pump on my 1980 230ge 4 cly petrol it is working, just! but its not 100% I have a clear fuel filter afetr it and when its running there is only a small amount passing through the filter and this is causing it to run badly ive actually got a couple of questions about it the first does anyone know the part number for this item its located quite far down on the side of the engine block ive had it off and by the look of it its not possible to service it, or does anyone have one lying about they would be willing to do a deal for how easy are they to get hold or are they quite rare, Ive also thought about missing this out altogether and putting a normal electric fuel pump inline but im not too sure if this will be too much fuel and too high pressure going to the carb thanks for looking ,don