Aftermarket fuel pump

On my 84 110 (RHD, petrol) I found a fuel pump on the right side frame just behind the front seat with a generic see thru type filter. Is this original? I cannot find in manuals and usually in fuel tank. It got my attention because of a clicking noise. Should I replace with a similar pump (great location for servicing) if so, any recommendations? Not sure of the condition of the one in the tank and if wires work, etc. Thanks.

Found my answer. Up to 85, some 110 had external fuel pumps - prc3901