I would think that the spreader would be necessary. We built one ourselve out of half inch think steel and an old puller. I can't imagine getting enough spacers in the carrier bearing preload without the room given by stretching. It will come apart (without stretching) though. If you can get the original pack back in with the original bearings then use the same stack and try it. Your preload will be close enough and you will just have to move shim thicknesses to get your back lash.
As to pinion seals, I use a chiesel to mark a line across the shaft and nut. On reassembly I tighten till the marks line up assuring no futher crush.
Owner 24 bay BSC
Bosch Master, ASE master L1
26 years MB technician
[This message has been edited by stevebfl (edited 03-30-2000).]