Fiberglass Piller Pod?

I am making a Triple Gauge piller pod for my 00+ impala.(They currently do not make one for my year yet). So im basically looking for advice to see if im doing this right, This is by far not my first fiberglass project. I have herd many things about fiberglass and plastic not sticking and I want to make this a one time deal. This is essentially what I did.

2nd: I took the donor piller pod that  I had left over from my last car(cavalier), Measured it up and marked where I wanted it to go. I cut the pod to size. and screwed it onto the piller so it didnt move around.

3rd: I used some body filler around the edges to make it smooth and make it look like it was supposed to be there. I sanded the crap out of the body filler so it was even with the pod.

Now I didnt sand the fiberglass yet, I also didnt rap the fiberglass around the piece onto the otherside. Im not sure if I should have. Here is some pics. any help would be great.

First, heres a bit of useless information.  I used to have that same design of bedspread...um, nevermind.

Heres how Ive been fabricating my components.  http://glassmanscustomforum.com/v-web/gallery/album1996?page=1  I dont start the same way this individual did in this case, but the concept is top notch.  I start by covering the complete pillar, therefore creating a replacement pillar completely fabricated of FG mat, note his first picture is only a part of a pillar.  Separate the pillar and your FG pillar, cut off the excess, deburr the edges, and TEST-FIT the component.  You can place your prefab pods anyway you like as this guy and I do with our PVC (pics 2-6).  I only cover what I need with the thin stretchy polyester cloths, attaching it with 2 part glues covering the pods as the pics show.  Also glue the faces of the PVC on the gauge side.  Saturate with resin, let cure.  Scuff all FG surfaces with rough grit (from 36 to 80 grit) sandpaper.  Use body filler in areas that require build up/contour.  Use a filler grater to remove excess and shape the areas as needed.  Scuff / smooth the area with 100-300 grit.  Use glaze putty (Rage Gold/ or whatever) to fill the small imperfections and such.  Prep-prime-prep again-paint/vinyl/carpet/upholster the new pillar .  Install gauges, wire them, and install.

Thats what I was gettin at. BUT, you explained it much better. there is no reason to keep the FG attached to the factory piiiar.

Yeah well I want it to clip in like stock so I want to use to stock piller and the gauge pod that I have made. I just need to attach them together. I dont want it to look custom. I am a little confused because both of you want me to make a mold and i just want to mold it together.