Here is one way to install 54 Merc taillights into your project. I will be showing how I put them in my 51 Merc build. The same technique can be used in many other models. The biggest issue with this taillight is the fact that the lense is relatively narrow. I will show a little trick later in the tech to get you past that problem. I first purchased a few lenses from one of the parts suppliers, a couple extra just in case. A lense surround was fabricated out of 3/8 solid bar stock.