Thank you both for your responses. Obviously I'm new at considering these matters, so it's breaking my brain a little.
I guess I got mistakenly hung up on the idea that the contribution from my savings equates to an after-tax contribution. What matters, if I understand correctly, is that I deducted the contribution that year, thus deferring $1000 worth of my taxable income, and in effect making my contribution a pre-tax one. So no double taxation.
SteamTrain, thank you for alerting me to potential issues with the seed money. I did have my own earned income that year, but I've no clue how they reported that contribution. I'll have to do what I can to find out.
