My SuSE collection. Request for info.

I have become a SuSE Linux collector. I have 6.3, 6.4, 7.0, and 7.1, with kernels 2.2.13, 2.2.14, 2.2.16, and now a choice of 2.2.18 or 2.4.0 Does each successive release contain only additional software or are there deletions too ? Can I pick and chose various portions from these to get a tailor-made system, or are there likely to be incompatibilities ? Where can I read about the differences between these distros ? Are they listed somewhere ? Best regards -- Geoff Bagley