Place potatoes (leave skin on) in a medium pot of cold, salted water. Bring to a boil, reduce to simmer and cook for approximately 15 minutes until tender when poked with a fork.
Cool slightly and peel potatoes while still warm.
In a medium sauce pan, whisk together water, flour, sugar, vinegar, dry mustard and eggs.
Cook over low heat, stirring constantly until thick. Cool.
Add mayo to cooked mixture.
In a large bowl, combine potatoes, chopped eggs, green pepper, onion and celery. Fold in dressing mixture.
Transfer to a serving bowl and top with sliced eggs.
Serve or refrigerate until ready to serve.