That's a famous quote ("You know my methods, Watson." http://www.bestofsherlock.com/top-10-sherlock-quotes.htm#methods).
That parallelogram, still in progress, it is something that can put a poor tatter to the test. Try and try again, it may be very different from that which I have expected... For now, I doubt there will be a tattingram by next week.
Browsing Pinterest, I found that a little book exists that has patterns to make the bobbin lace version of the tangram. Let's see, mmm... It seems a Dutch publication from 2005. The link for the image is not broken but it doesn't link to the designer's site, you know what I mean :( ...
I investigated, of course. I discovered a pdf (http://www.dentellieres.com/Materiel/images/DeMeester.pdf) where the book is listed and from that I followed a couple of French links, then discovered a Foundation: http://www.kantopleiding-nko.nl/index.php/algemeen.html
... and eventually I found it:
There's an email there, in case you want it be sent. Me? I'd better try to finish my parallelogram...
Tot gauw –> See you soon
( http://blogs.transparent.com/dutch/29-ways-to-say-goodbye-in-dutch/ )
What? 29 ways!!!