Monteverdi Sierra article

In the Monteverdi FB group the following post was placed:

https://www.facebook.com/groups/MonteverdiAutomobiles/permalink/10156502243898326/

Seems like a copy and paste from this quality article:

https://www.allpar.com/cars/adopted/misc/monteverdi-sierra.html

Which also states a number of 20 had been build (including the two convertibles).