The year-end value to enter is the total amount that you had in traditional IRAs (which includes rollover, SEP and SIMPLE IRAs) of which you are the participant. Do not include any Roth IRAs, any non-IRA accounts line 401(k)s, any IRAs maintained for your benefit as beneficiary or anyone else's IRAs.
Your basis in nondeductible traditional IRA contributions belongs to you, not to any particular one of your traditional IRAs. For the purpose of From 8606, all of your traditional IRAs are treated in aggregate as one large IRA.
