It doesn't sound like what you have ( a two page letter) would be sufficient to meet the regulatory requirments for appraisal content. SR 94-55 from the Federal Reserve contains the following statement: (note-It may be somewhat outdated but it does provide some guidance on the regulatory thinking in terms of what is sufficient support to constitute an appraisal).
"The Restricted Report provides a capsulized report with the supporting details maintained in the appraiser's files.
The agencies believe that the Restricted Report format will not be appropriate to underwrite a significant number of federally related transactions due to the lack of sufficient supporting information and analysis in the appraisal report. However, it might be appropriate to use this type of appraisal report for ongoing collateral monitoring of an institution's real estate transactions and under other circumstances when an institution's program requires an evaluation."
Not a legal opinion, just my personal opinion.
"A nickel isn't worth a dime today."- Yogi Berra