Having read a few threads of guys having issue sourcing these for builds, especially in the US
Here is two places that have the Toshiba version in stock, one is Germany the other Spain.
http://www.tonalityeffects.com/clonewerk/index.php?k=29
http://www.retroamplis.com/epages/62070367.sf/en_GB/?ObjectPath=/Shops/62070367/Products/DI-1S1588
Glenn :)
The one in Spain is my personal supplier (his house/shop is at 15 min by car from mine), a decent guy. Although 2.50 € /diode seems quite expensive to me.
I'll be needing a few for Ben's QoB but I expect no problems with substituting them with 1N914s...
The QoB sounds great using 1N4148's for all of the clipping diodes.