It is an unusual position for the Revenue Commissioners to be in, languishing among the unsecured creditors in an examinership. Yet that is exactly where the tax body finds itself Wednesday evening as the High Court, sitting late, considers a challenge to a salvation plan for the Irish operation of troubled Newry fit-out firm, Mac Interiors.  Revenue’s usual status as a preferential or super preferential creditor in this type of restructuring has been stripped away and it’s now trying to block proposals to save the business over a whopping €13 million tax debt. The proposal would save jobs and the…