I have had 3 NOS bagged 1750 Bootlid scripts come in. I believe they can also go on the Duetto 1750. Part number is 105.44.56.230.00
These are VERY rare in this condition and the first NOS ones I've seen appear on the market since I started looking for parts 24 months ago.
(http://www.ar10537.com/img/p/215-905.jpg)
I also have a Hellebore Spider horn cap. part # 105.62.23.057.02
(http://www.ar10537.com/img/p/214-901.jpg)
They get listed on the website two days.
;D