1. Hopefully Vanguard did a proper trustee-to-trustee transfer so that the transaction is nonreportable and no Form 1099-R is issued, otherwise there is a complication of having rolled over an RMD.
2. You were required to complete his 2023 RMD and you did so by making the QCD. You'll receive a 2023 Form 1099-R in your name. Nowhere on a tax return is there any indication that a particular distribution satisfies any part of an RMD. When TurboTax asks if any portion of the distribution reported on this Form 1099-R is an RMD, you'll answer Yes and indicate the amount of your husband's RMD. (This is only to allow TurboTax to disallow reporting any of the RMD as having been rolled over.)
Distributions made after your husband's death are your distributions, not his, and go under your name even though the distribution might be to satisfy his RMD. The responsibility to complete his RMD became your responsibility upon his death.
It's not clear to me whether the spousal 401(k) is an inherited account or an account where you are the participant. I suspect that it might be an inherited account which would make little sense since you are over age 59½. Your husband's RMD for the 401(k) (if he had separated from service from the company sponsoring the 401(k) and had not already completed this RMD) was required to be distributed to you before or concurrently with rolling the remainder over to the spousal 401(k). I would expect that you would receive a code-4 Form 1099-R combining these distributions.
You'll be required to take RMDs from the IRA beginning with the year that you reach age 73.
If the spousal 401(k) is an inherited account (with distributions being reported with code 4), it would seem to make sense to roll the 401(k) over to your IRA, otherwise you'll have RMDs beginning in 2024 using the Single Life Expectancy table instead of lower RMDs using the Uniform Lifetime table beginning with the year you reach age 73.
