Hi Mark (and welcome to the community),
When you say the user is not able to see any previous runs/history, what exactly is not visible and where? Previous runs in the inventory tree, in the log panel, runs by other users, runs happened some time ago with vRO client closed and reopened since then?
BTW, you may consider another way to ensure that your workflows are not editable on the prod machine. On the dev machine, you can put the workflows you work on in a vRO package and then export the package to folder as set of XML files, which you can put under source control system like Git. Then, when you want to deploy them in prod, you can assemble the package binary and 'seal' its content (the workflows) which will make them effectively un-editable, and then import the result package binary file into prod vRO. That's the approach used by most vRO plug-ins to distribute their content.