Fitting twin carbs/ seats

After rebuilding my B18 to take twin carbs, I have suddenly realised the linkage from the accelerator to the carbs may not be the same as on a 121 zenith single downdraught. Any advice, or do i just have to source some new linkage fom another car.

Also can I cut the top off of a stromberg single carb inlet & outlet manifold (cast in one peice) to just use the twin exhaust ports, so I can fit a twin downpipe to help the engine breath.(because the twin carbs already have alu. inlet)

Also top tip for the day, always cut any holes in new floor pans BEFORE you weld them in. Finding where the seat attachment nuts under the floor can become ploblematic..DOH

Also has any one a very good passanger seat back in Red (leatherette effect)where the stiching is not splitting..and is at a reasonable price..