Regulation M applies to all lessors of personal property under consumer leases that fall under Section 213.2(e)(1) and (h). The record retention requirements can be found in Section 213.8 of the Regulation.
Link to the Regulation: https://www.ecfr.gov/cgi-bin/text-idx?SID=2240159c84d2d3b48422a5185ff69dea&mc=true&node=pt12.2.213&rgn=div5