So heavy buffing and refinish is established, but the gun just does not appear to be a
factory 2" gun. The front sight is too far forward being all the way to the front of the rib. Front sights are always set back. If a flat blade, it should be pinned, as noted above, the 5th model is forged, but some 2" 5th Model Safeties exist that are pinned. With the buffing, and heave plating, maybe the pin is buffed smooth to the rib? Also, forged front sights on these revolvers have a sight base, but yours does not appear to be anything other than a thin blade set in a slot. Pictures of the top of the blade and the muzzle would help out. Lastly, I do not think that the company ever used the term Bicycle Gun on any 38 caliber Safety revolver.