I do have a David plane Kevin, and as lovely as it is it could be better
I've just ordered the Ripmax plane having seen this pic of the rear:
It looks like the two allen key adjustments will enable controlled inching of the blade in and out as well as centring... Well that's my hope.
As to blades, the only pics I've seen are blades in wrappers, but they are labeled 'Feather' which is a Japanese company that makes lots of blades, but looking at the wrapper it is my hope they are old fashion double edged razor blades, ie dirt cheap if bought on the internet, but also available at supermarkets... and I already have quite a stock of them. But this is all guess work, I'll report back once it's in my hands.