Thank you for such a timely and comprehensive answer.
So, to sum up: One can withdraw partial amounts from a traditional IRA and deposit those funds into a Roth IRA without causing an early withdrawal penalty. Of course, one pays tax on that contribution to the Roth IRA. No intermediate rollover IRA is needed; as well, since both accounts at at the same custodian, this should make it easier.
I've already maxed out Social Security tax for this year, so the effect on AGI is not an issue.
Nice advice on incrementally testing amounts to see how tax liability changes.
