18 months in and everything, I mean EVERY aspect of my project has changed in some way, or been scrapped. I think its the exception rather than the rule for all work to be included in the final thesis - everyone I know has had to scrap months of work somewhere along the way. If you've already written stuff up, don't delete it, definitely save it somewhere as it may well be useful at some stage. Any way of including it as an appendix or a subsection somewhere?