HCCS Econet Module
As far as I know, this is the only contemporary third party Econet module made for the 8-bit machines. Exactly why HCCS decided to make their own version isn't clear to me. I don't know what other involvement, if any, they had with Econet either.
The principal difference between this version and the usual Master interface is that the components are all on the underside of the module. The circuitry appears to be very similar to the Acorn type although it looks as if the 68B54 is made by ST Micro and not Motorola.
These pictures have been kindly provided by Matthew Cook as I don't own an HCCS module.