Bob, with regard to edger blades, Alroh still makes them as spare parts for the later Imp version that Ty has, and they are available from the Outdoorking online store, along with the mounting hardware:
https://www.outdoorking-forum.com.au/index.p...s_id=48&zenid=7i76no4d29kvt2bpr4iav0iq42

I actually measured my blades and I think they were probably only 6" long when new, and are about 4.5" now. I'm trying to figure out how the replacements can be 1/2" thick, as the online store listing says, when the replacement retaining bushes are the same as mine and only allow for 16 gauge blades. It is a puzzlement.

Ty, can you tell me how thick the blades are on your Imp please?