If a Tenant-Landlord verbal agreement is made, and documented (with this wording), is it enforceable?

At end of a confrontational final inspection, the Tenant and Landlord verbally agree to settle all items for $65. 3 weeks later, Landlord sends a bill for $100 and says expenses were higher than he estimated. Thus, breaking the verbal agreement. Does this qualify as documenting the verbal agreement (via email exchange): ** Tenant: "The gentleman's agreement you looked me in the eyes and shook on was $65." ** Landlord: "That was because I did not think the screen repair would be more than $15. What we agreed to was the tub & screen repair." To me (the tenant) his (the landlord's) first sentence documents his concurrence that a verbal agreement occurred, and that is was for $65. Is this strong enough to use as a defense in small claims?