I take it, it's one of those SIP-5, beveled slab package, common emitter types?
Using independent rather than monolithic pairs only increases the offset voltage (especially due to thermal drift), and the distortion marginally. If you want the best replacement, hunt down a monolithic pair; if you just want it working again, use anything.
Note that "matched pair" transistors are available (especially in SMTs?), but they are independent dies on separate lead frames (well, the lead frames are just leads anyway, of course they're separate). The thermal matching is pitiful, typically something like 500 K/W differential thermal coupling between dies.
The schematic can tell you can tell how sensitive it may be. If the diff pair is operated at high voltage, the change in power dissipation will be large. If the common mode voltage range is small, a cascode could be added, significantly reducing the voltage drop on the diff pair. (Which may also bring the power dissipation within the realm of a SOT-363 device, if that's the only sort of thing you can find.)
Tim