The 71 deg C. thermostat was used on Grp. 4 ex works engines. This is the only place you can buy this , thus I am posting in Connections even thought this is e-bay based store called ;
"Fiat Lancia Abarth spare parts"
The price is 146 Euro !!!!
This is very expensive place, but sometimes the only place to buy 124/131 Abarth parts (like Abarth diff cover, Abarth diff seals set, etc. )
http://stores.shop.ebay.pl/Fiat-Lancia-Abarth-spare-parts_ABARTH-Fahrzeuge_W0QQ_fsubZ13QQ_sidZ70009841QQ_trksidZp4634Q2ec0Q2em322 MIRO