Like this, but make sure you get one that fits a Puma:
http://cgi.ebay.co.uk/Oil-Pressure-Gauge-T-Piece-Adapter-Union-Ford-Mazda-etc-/140415155107?cmd=ViewItem&pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item20b1653ba3" onclick="window.open(this.href);return false;
Remove Ford oil pressure switch and screw in adaptor. Ford oil pressure switch screws into end of adaptor and after market sender screws in the other hole.