Good job on the fit, The match of barrel to kit looks perfect as far as I could see in a pic. Sometimes the fingers see things that the eyes can't, but it looks good from here. I can't tell for sure if you were able to keep the alignment of the two barrels the same as it was in the original blank. Sometimes the pattern changes enough between the two diameters to make it harder to be sure. If I could see it from all sides there is probably at least one spot where a sharp near vertical line crosses the centerband, and that will tell the tale. I always mark my blanks at least two or three ways to try to keep straight which end was in the middle, and which one was on top, and where the two pieces are in the same alignment as they were when square. Most times with pr, there will be 4 distinct "sides" if a cylinder can have sides. blanks that have a lot of pearl in them tend to have two "shiny" sides and two darker or plainer sides. Must have something to do with the way the pearl either settles or floats after it's in the mold but before it sets up. But in any case, if you got them back in the same relationship, that's always a mark of a careful penmaker.
I have never made this particular kit, so I am not sure about this one, but I'll mention it anyway. The visible silver band at the top of the body just below the centerband throws off the flow of the pen, to my eye. I believe on most kits, it usually tucks up into the centerband. Did you maybe not push the pen together all the way, or possibly trim the top section a little short so that it doesn't fit up in there out of sight? If this kit requires you to part down to the tube to slide the centerband on, it could be that the bottom of the tube is too long and is keeping the tranny from sliding up all the way? If so you don't have to disassemble it, just use a deburring tool or reamer to remove some of the tube inside and then take a drill bit or transfer punch and roll it around inside the tube to flare the ends out and up against the bottom of the centerband assy. Or it may be that this one is supposed to show and I'm way off base. It happens sometimes.
And lastly, I can't tell for sure what that black stripe reflecting the length of the pen is, but it does throw off the reflection of your lighting and make the finish look less shiny than a single bright line from 1 direct light source (or "shine line") would. Are you perhaps shooting on top of a white counter, and the black line is the edge of the counter top and the unlighted area below counter level? Overall your photo is good, color balance is good, focus and depth are good, and the white background is clean and neutral. You just need to be mindful of the reflection of what's behind the camera as well.
Overall a really nicely done piece of work, and these are just a few things to keep in mind more than criticisms.