Need Help With Onc. ampliatum & sphacelatum

[AaronM]

I have two Onc. that I could use a little help with.
The first is an Onc. ampliatum that I have mounted on a piece of cork. This is an orchid I rescued that was in very poor condition (sunburned and shriveled ) which is recovering nicely but has not shown any signs of further pseudobulb formation during the past six months. I keep it in my orchid room where the temp. is 65-85 degrees and 50-60% humidity with medium to bright light.
The plant has three psuedobulbs and maybe four new roots that are bonding well with the bark on one side of the plant. However the older roots, although white and firm, are not growing and are preventing good bonding along the other side of the mount. What can I do to stimulate more roots on that side? Also when can I expect some new growth from this plant? Lastly I could use any general care advice that anyone has to offer.

The second orchid is a 50 lb, mammoth Onc. sphacelatum with around 50 pseudobulbs and 5 spikes approximately 4 1/2 ft long. The only medium this plant is growing in is a massive mat made of thousands of old roots. This plant was also in pretty bad shape and had been sitting in on the ground for about a year. It is now hanging inside an east facing pergolla that is shaded for about 3/4 of the day.
I had to trim a lot of damaged leaves and tore out nearly 20 rotting or dead bulbs when I first brought the plant home and it seems pretty happy now.
What I find strange is that it is spiking and has been since January and has also been forming new pseudobulbs for the past ten weeks or so. Is this type of concurrent growth normal? Also, how long does this plant usually take to flower after it spikes?
The center of the "colony" is bare of psuedobulbs and I was thinking of moving a few of the actively growing clusters of bulbs from the outer edges to the empty center (after flowering, of course). Is this a good idea? When would be the best time? And should I add some medium to the center or just wire the transplanted sections in place?
Thank-you for any help you can offer.
Below are some photos. The one gallon watering can in the last picture is for scale.