Dogs and 1962 10 wides

We have 5 old 10 wides in our 12 lot park. In Jan of this year we gave all the homes to the (home rental) tenants. One tenant became ill and moved out. The problem is it is a really old steel home in fair shape, oh and filthy inside. My wife wants it gone but we have someone who wants it (free) and we already have 1 vacant lot. Do we keep the income or improve the property and replace it with a newer home (there is room). This brings me to the dog issue. This applicant has a 60# mixed breed dog. Our lease states no dogs over 25# but with this park we inherited 2 large dogs and found out that another tenant has a large dog also. Now that it is an all homeowner park do we allow larger dogs up to 60# or so? It is a lower end park in a rural village. With 5 star cash flow!