You could probably use an old analog scope as a buffer amplifier in front of both your DSO and signal tracer. It would require you to change vertical attenuator settings on the analog scope, though.
Some of the higher-end DSO's have a signal out, one example is the Tek TDS5000 series, but these kind of features are often skimped on with the low-end, bottom of the barrel instruments like the Rigol, and even the low-end instruments from brands like Agilent, Lecroy and Tek. There's nothing preventing a digital scope from having an analog output, it's not like the signal is digitized before attenuation/amplification.