Mixed age couples

Can anyone please point me to the exact part of the DWP Decision Makers Guide which incorporates DMG Memo 1/19 (changes for mixed age couples) following the coming into force of SI 2019/37, particularly for specific guidance to DM’s regarding the savings provision in Article 4.

DMG Memo 1/19 was replaced by Memo 7/19, which was in turn incorporated in the DMG in Chapter 77 at Para 77035 (insofar as the Memo discussed the savings provisions).

https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/945908/dmgch77.pdf

Many thanks Charles.  Appreciate that.