Came home and did some research on the 'net and found this fantastic tutorial. Took a few minutes to actually process the information, but once I had - it made perfect sense.
So, this morning, took them up - and they are perfect! Basically, it's a tuck on the inside of the jeans, but the stitching is so very close to the original top-stitching, that you can barely tell! I ironed the tuck up into the leg, and used a little fusible webbing to hold it flat on the centre front & back. Just for my own peace of mind.
With the waist size, I make a slit in the inside of the waistband near the sideseams and thread elastic through until it gathers to fit. I handstitch this closed and you can hardly tell I've ripped!
Here's the back view - the elastic isn't that noticeable once they are on because they fit so well, and I wear my shirts over!
Now it's time to get out of my jarmies and into the morning!
Smiles, Mrs R