The canopy that came with the RVHP kit was not acceptable, which meant making my own. This is near the bottom of my list of things I like to do, but sometimes it's unavoidable. Making a decent replacement canopy is half the battle. The other half is making it fit the model. In the case of this TF-102, the decking where the windscreen would be placed was kind of a mess in its own right. So after building up areas with sheet stock and epoxy putty, careful trimming, fitting, trimming, fitting, etc., eventually resulted in a windscreen that settled in its location -- more or less.
After carefully tacking it in place with superglue, I mixed a bit of thick superglue and talcum powder and with a sharpened toothpick, worked it under all the edges of the the canopy, fixing it in place and filling any gaps in the process. Much more glue/filler ends up on the fuselage than underneath the windscreen.
With a strip of masking tape protecting the clear part, I attack the mess with a coarse sanding stick, grinding and scraping the excess away.
This results in significant scratching, which I fill with Bondo spot putty. This stuff dries very quickly when just smeared into scratches.
To sand the putty down, I use a strip of balsa with one edge shaped to an edge, wrapped in some used 400 grit wet-or-dry sandpaper. This provides a sharp edged sanding block. (Trailing edges of surplus kit stabilizer and wing pieces work well here too.)
Careful wet-sanding does the trick.
This is followed by a heavy coat of auto primer to fill remaining scratches and show any remaining problems. In this case, there were no putty refills to do. I let this set-up overnight.
The primer is sanded down with some fine-grit sandpaper...
...and the protective tape is removed. Not bad. Once the framing is masked and painted, it should be quite acceptable.
And that clamshell piece was a whole 'nother story...