Snowy, I would recommend installing your original parts and selling your mods on NASIOC or toronto-subaru-club. It is a bit tough to sell modified WRX; it usually sells for LESS than their market value, especially if you had some power mods.
I am a member of the TSC I posted my quandary on the site. I have received many responses and e-mails regarding the mods and methodology in removing them to prepare my car for lease return and/or trade. One was from a very accommodating Subaru dealer in Southern Ontario. This may work out better than I anticipated.