Hello Juan!
Thanks for the suggestion. As the saying goes, been there, done that... and have not received a response from anyone at a number of Sigma offices that I've written to. Making a phone call to HK or the nearest country may also be a waste of money as I surely am going told to get in touch with the local distributor.
Being (in NZ and) off the beaten track, we are not so fortunate to have a Sigma office around the corner (the nearest one being in Hong Kong!) and as with distributors... if it ain't worth much, they don't bother.
I guess that I will have to be content with one of those after-market, metal or rubber hoods... but I've fallen in love with the petal shaped ones!
Have a great day!!!
John