Lawn equip. disagreement

In April, 2005, I purchased pre-owned 60" Dixie Chopper for $2200 and presented it to my dear (retired) friend and neighbor of 10 years to use to continue to mow his and my lawns, as well as a widow's lawn down the street. This was his main source of physical activity and something he seemed to enjoy. In the meantime, I have moved from that house but not sold it yet, and left the mower there for him to use. He passed away several weeks ago, and his son has since removed the mower from the premises without mention of position or intent, and apparently left the mowing responsibility to a cousin's husband. I don't feel obligated to this son, partly because he is more financially secure than I, and the fact that he removed the equipment to another location and now I have to make other arrangements to get my grass cut until I sell or rent the home.
Advice,comments, and suggestions please; Legal, personal/moral.

Did you gift the mower to your friend or was there an agreement that the mower was just there for him to use?