I had a local company build us a cabinet with P/I and I/P's put in the cabinet.We mounted it next to the new PLC and tubed the signals in and out from the old pnematic memonic board. It worked perfectly. We had the deltaV screens redraw to look just like the old board and the operators didn't miss a lick.
It was 1/10 the cost in 1/3 the time. The cut over was done on the fly, one loop at a time. No need for postioners as the valves and the loops were already tuned and calibrated.