I would expect the letter to identify the form of authority being asserted. Then it's up to the plan administrator as to whether or not it's reasonable to accept.
In the absence of receiving a letter informing the plan that the mailing address for the now deceased participant should be updated as indicated the 1099r goes to the same address the plan has in its official records.
Yeah, I'd love to see the ASOP 51 disclosure on one of these. $ to donuts they are taking the position that the deductible amount is the purview of somebody else. Nasty surprise awaits the client.
You need to search this forum for a copy of Larry Starr's outline of this topic. In the case of a sole prop I usually start with the SE. But the doc might call for other adjustments. It can get complicated.
Something does not make sense to me. Every davis-bacon plan I've ever worked on provided much more than top-heavy minimum to the davis-bacon participants. Otherwise it is not taking advantage of the davis-bacon provisions.???