Interesting because I just sent one off to one of my good clients about 15 minutes ago.
You handle them just as you would a normal FHA. I tend to include addition photos if necessary and make additional comments about condition, the market, etc. since these appear to be well scrutinized by the UW. One thing with this client, even in a low density rural market, I make sure that the first 3 comps do not exceed 12 months due to the declining values. In addition, in this one, the subject was in a great condition in a good demand sub with proximity to Lake Michigan and a connecting inland lake (non-waterfront) with only 1 sale of a similar size 1.5 story modular house on inferior lot with no basement. I just made sure that the physical attributes of the houses, the reason for dissimilar style comps and the distance to the majority of the comps (10 to 13 miles) was fully explained in the report.
I personally like doing FHA reverse mortgage appraisals, primarily for two reasons: #1) The houses are generally in really good conditions which makes the analysis easier and less problems explaining condition and deferred maintenance and #2) The HO's are older folks who have lived in the house for a significant period of time and are really nice to work with and visit with during the inspection. Thre has not been one grumpy HO in all of the reverse mortgage appraisals I have completed.