My husband was born 03/06/1952 (prior to 1/2/54) and is grandfathered under the law passed by Congress in 2015. He intends to stop working within 6 months.
My birthday is 10/16/1956 and at this time, I continue to work FT .
Can my husband file a restricted application for spousal benefits on my SS, allowing his SS to grow until he is 70 years old while I am not claiming SS benefits.?
No. You would actually have to be drawing your benefits in order for your husband to potentially receive spousal benefits. And, if you're still working, both your benefits and your husband's spousal benefits could be subject to full or partial withholding based on Social Security's earnings test (https://www.ssa.gov/planners/retire/whileworking.html) until you reach your full retirement age (FRA).
Say for example that you filed for your retirement benefits effective January 2019 and your husband filed for spousal benefits on your account. If you earn more than $17640 in 2019, $1 of the combined benefits payable on your record would need to be withheld for each $2 that you earn in excess of $17640. That means it's possible that neither you or your husband could be paid any benefits on your record depending on how much you earn prior to your FRA.
It sounds like you and your husband have a number of different possible filing options to consider. You should strongly consider using our software to fully explore and compare your options so that you can choose the best possible strategy for claiming your benefits.