Here is an update:

Summary: Originally I started looking at a solution which would run under my trusty winXP-32 system, QX9650 (quad core), MSP11, but found almost nothing. There was DEFISHR,l-us.html
but that is a standalone program.

All the products I found need either a later OS or winXP 64-bit. Boris FX and Prodad Mercalli were two such examples.

I was sure there was old stuff out there (because this requirement is hardly new). It could be some old version of the above programs. But the companies refused to discuss (or sell me) old versions. Some of the emails were just bizzare in how they avoided giving a straight answer.

Eventually my winXP-32 PC started giving some problems and I built a win7-64 PC. It tooks me weeks to move my many apps (many of them extremely pricey old stuff which cannot be replaced; some had to run under a winXP VMWARE VM).

So I went to MSP12 which is natively 64-bit and this opened up the NewBlueFX Lens Correction plug-in option which can be bought in a $99 collection (their other stuff costs way more).

Here is a little video showing some of the lens correction. At the end is a bit which was corrected using the Sony Distort plug-in which comes with every Vegas (including 32 bit) but it's use is limited to specific types of scenes

I used the Sony Distort method in various previous videos e.g.

That one is of much better quality anyway because the camera is externally mounted. I need to repeat the NewBlueFX with an externally mounted camera, because (a) the camera is then in a waterproof housing which affects the distortion slightly, and (b) the camera is looking "down" more.

What concerns me is that there doesn't appear to be a lens correction method which does it correctly. This can't be rocket science. But maybe these cameras don't generate a simple distortion pattern e.g. pure barrel?