Gentlemen, let's do some dissection of the circuit:
1) The schematic IS there. It is a 276k GIF. My browser didn't show it, so I just copied the link into a download manager and let it download it to my machine before viewing it. It took quite a while (several minutes) but after downloading it I could see it.
2) The buffer stage looked odd to me initially due to the assymmetric biasing resistive divider (9.1k and 22k). My first thought was, aha! that will introduce assymmetric clipping. No. The 10k resistor at the emitter of the transistor is seen as a 1.5 to 2.5 Meg ohm resistor at the base, which in conjunction with the 510k base resistor and the 0.6 or so Vbe voltage drop leaves you with roughly 4.5V at the emitter output.
3) The clipping stage is of the TS kind, however the (-) input cap and resistor (220nF & 2k7) have a corner frequency of 267 Hz instead of the typical 718 Hz of the classic TS / Boss SD-1. More bass are let through.
4) Looking at the clipping diodes, there are two in series of a less known type: MA165. First, having two of them produces more apparent clipping than just one since the contribution of the clean signal component at the output is smaller in comparison to the two-diode voltage drop of the distorted output. Second, someone suggested those diodes have a 0.9 V forward drop and may not be made anymore. There is no particular mojo in these diodes. I downloaded the MA165 datasheet by Panasonic and verified a 0.95 V drop at 100 mA, which is far more current than the microamps you'll actually have in the feedback loop of the opamp. Then, I downloaded the 1N4148 datasheet by Hitachi, and found these diodes are essentially the same in terms of average diode current capacity, recovery time (both are fast), and also verified that at 100 mA the 1N4148 has a forward drop slightly above 0.9V. Bottom line: you could use two 1N4148 in series.
5) The feedback cap is 51 pF which is pretty stock, so nothing new here.
6) The opamp is of the rail-to-rail output kind. Looking at its datasheet you see the output configuration is nearly identical to a CD4049/69 inverter. Also, the numerical values indicate the rail-to-rail capability is degraded with increased loading, just as in the CD4049/69. This might add some additional compression to the sounds, particularly during the initial note pick or when strumming chords hard. Whether this effect is noticeable or not is open to discussion. The TLC2262 seems like a sensible substitute for this opamp.
7) Then, there is a three-band tonestack. I haven't had the time yet to redraw the circuit in a more traditional way, but apparently it is similar but not exactly a Fender or Marshall device, since I see at least one too many capacitor and resistor in there. Certainly a design to be further studied!
Next, there is a gain recovery stage formed by the second opamp. The thing to keep in mind here is the 47k and 1nF in the feedback loop that filter out the high frequencies starting from 3377 Hz. This certainly tames the srhill.
9) Finally, there is a transistor buffer stage pretty much standard.
To summarize, the particular aspects that might make this circuit different are:
a. Lower bass cutoff frequency (267 Hz v/s 718 Hz)
b. Use of two diodes in series in the clipping stage (varies the clean to distorted mix--this is inherent to this particular type of clipper and has been discussed previously)
c. Rail to rail MOSFET opamp--perhaps
d. Three band customized passive tonestack
Regards.
