I buy a Gamefisher 15 hp and when we start fixing it we find out the thermostat system is missing. I found all the parts number needed but some of them are no longer availabe. These are the parts:

Mercury-Mercruiser 823694 INSERT Thermostat OBSOLETE**
Mercury-Mercruiser 27-819669GASKET Thermostat Cover. OBSOLETE**
Mercury-Mercruiser 24-819329SPRING Thermostat OBSOLETE***
Mercury-Mercruiser 819321 COVER Thermostat OBSOLETE***
Mercury-Mercruiser 10-819382SCREW (.250-20 x 1.00) OBSOLETE***

Does anyone know were I can find this parts or if I can adapt a new thermostat system to this engine??