CopyPasteValues.cs

using System;
using UnityEditor;

public class CopyPasteValues
{
    const string kBufferName = "json-copy-buffer";
    const string kTypeName = "json-copy-type";

    [MenuItem("CONTEXT/Component/Copy Values With Json")]
    static void Copy(MenuCommand command)
    {
        SessionState.SetString(kTypeName, command.context.GetType().AssemblyQualifiedName);
        SessionState.SetString(kBufferName, EditorJsonUtility.ToJson(command.context));
    }

    [MenuItem("CONTEXT/Component/Paste Values With Json")]
    static void Paste(MenuCommand command)
    {
        var json = SessionState.GetString(kBufferName, string.Empty);
        EditorJsonUtility.FromJsonOverwrite(json, command.context);
    }

    [MenuItem("CONTEXT/Component/Paste Values With Json", validate = true)]
    static bool PasteValidate(MenuCommand command)
    {
        var json = SessionState.GetString(kBufferName, string.Empty);
        var copyType = Type.GetType(SessionState.GetString(kTypeName, string.Empty), false);
        var type = command.context.GetType();
        return !string.IsNullOrEmpty(json) && type != null && copyType.IsAssignableFrom(type);
    }
}