In addition, reichelt.de has got these sockets for crimping; they call them IC socket for flat ribbon ("IC-Sockel für Flachkabel") - but only up to 32 pins. I'm sure you can find larger ones elsewhere.
Conrad.de seems to have 40 pin ones (742120 - 62), at least the pin side. The socket side may be very difficult to find, possibly you can find something to plug in between. :-)
... Oops - of course you'd need a 48 pin version - phew, that's a tough one. I don't think a 28 and 20 pin would fit next to each other...