My PeeWee was built in the 2 stage configuration. I knew that was asking for trouble but the trouble set in well before the first launch. I seemed always to break it somehow while taking it out to a launch.
The first few times it flew was always with sustainer only and I managed to get it back. The one time I tried a 2 stage configuration, the sustainer was lost. I did find it a few months later while looking for another rocket but, by then, weather and cattle had taken their toll. The booster is still sitting in my garage waiting for a sustainer rebuild.