The correct way for uploading photos of homebuilts is to use the designer or kit manufacturer's name as the manufacturer's name.
An example is e.g. the Van's RV
-6A: Van's is the designer and kit supplier, but e.g. in the US Register they are listed with the individual builder's name as the manufacturer. So you have e.g. an Achelis Scott RV
-6A, an Ahrens David Lee RV
-6A, a Rudolph Richard W RV
-6A and 1300 or so more.
Above, an "Amateur Van's" RV
-6A and a "Barron Glenn" RV
For our purposes this is unworkable, so we would list all those as Van's RV
-6A. If you like, you can give the name of the real builder in the Remarks field.
In this case the generic type would be Van's RV
-6 (generic types are without version pre- or suffixes), and the version type would be Van's RV
-6A (thus including the version letter "A"). Please remember that the manufacturer's name must be listed both in the generic type and in the version type!
Of course, not everybody is a homebuilt type expert, and it can sometimes be (very) difficult to find out the designer or kit supplier. What you can do is the following: take only the model number from the Register, and then do a Google search with it. With a bit of effort the designer or kit supplier can often be found. It is fun and it will increase your knowledge quickly.
Of course, there are also unique aircraft, designed and built by an individual who is not selling plans or kits. In those cases, only use the family name of the individual as the manufacturer's name, the forename(s) can be listed in the Remarks field. E.g. the aircraft listed in the Register as a Haich Nathaniel 1600 would be listed as a Haich 1600, and in the Remarks as "built by Nathaniel Haich". In the US Register, the family name is always given first.
Some homebuilts are already on the upload page, like all the Van's aircraft. More will be added in the future.
The example given by Paul, N102ML, is a difficult one, as it is or a unique design, or the builder has given a different name to another designer's aircraft (which is allowed in the US!). It is listed as a Bowden Michael B TWO EZ
-MS1. When no original designer can be found, this aircraft should be listed as a Bowden TWO-EZ-MS1, with "built by Michael B. Bowden" in the Remarks field. However, I think this aircraft might be a Rutan Vari-Eze or Long-EZ, but I would have to see the picture for that.
Chief Database Editor