Here is our next project. We are at the early drafting stages of the universal 1U frame that can hold up to four channels of modules.
At first we planned to make only mic preamp modules, but then it occured to us that some other modules will actially be quite useful. For example, 1073-style equalizer can be a perfect match for 1073-style mic preamp. This will allow to put two channels of full RN73 type preamps with equalizers into 1U enclosure (with external PSU).
Besides RN73, there are plenty of other preamp modules that can be built in this frame. We are planning to make an SSL9K and REDD preampls among the others. Actually, front panel layouts for RN73 and REDD are ready. We will be designing PCBs shortly.