LM348 replacable by LM358
It should work more-or-less. The LM348 is kind of a quad \$\mu A741\$, so it has a class AB output stage.



The LM358/LM324 has a different kind of output stage that is more prone to crossover distortion. You might want to use a pullup resistor of 5 or 10K from the sine and triangle outputs to +9V to help reduce crossover distortion (by forcing it into Class A). 



You could also use a 4558, which is more common and thus may be more easily available to you. 



Using an op-amp as a comparator, as they are doing (looks like one of the late Peter Crowcroft's circuits?) is not the best- slew rates will make the square waves less square, but that's kind of inherent in the current design.