There are no federal requirements for all of the record retention requirements. These are typically state issues less the occasional 2 years on some consumer regulation, or whatever a specific requirement is. I know of none applicable to IRAs.
My recommendation is that absent a specific requirement, and there are very few, you look at the use of the documents in question. What is any related retention period for supporting items that lead to these, is it a regulatory or IRS issue? Will examiners want these during our next exam, and when is that exam? What is the active litigation exposure period on which these would support the bank? That is, if you could be sued for 3, 5 or 7 years, retain them for that period as they may be crucial evidence. And ask when you last used those dated documents and what role they played? In most cases these are retained electronically so having a warehouse full of bankers boxes isn't an issue. In short, absent a rule, create your our guidance based on use and risk because not having it doesn't violate a rule, it may just be an inconvenience.
As to having to save the paper, I recall counsel telling me most any competent attorney can get an electronic copy admitted a evidence. Ask your bank's attorney what they prefer to have an original of or what originals are actually required vs preferred.