There have been a few requests for this one. Let me know if you build it and it works. This should fit in a 1590B enclosure.
Update (11.10.2012): Revision 1; changed Q3 and Q6 to 2N5457s.
Update (22.01.2012): Revision 2; I had mistakenly labeled this as requiring 44 cuts while it only needs 43. Thanks to Nocentelli for spotting this.
Update (01.02.2012): Built this one tonight. Had to reorient the depth and rate pots (layout has been updated), but otherwise it worked like a charm.
Update (18.12.2012): Voltage readings from my build as requested:
Power supply: 8.88V
All pots fully CW.
Update (30.04.2013): Just adding the schematic that I drew based on the trace made by KindaFuzzy over at FSB.