(a) Courts Other Than District Court. The court, after verdict or after a finding of facts under Rule 52, may report the case for determination by the appeals court. If the trial court is of opinion that an interlocutory finding or order made by it so affects the merits of the controversy that the matter ought to be determined by the appeals court before any further proceedings in the trial court, it may report such matter, and may stay all further proceedings except such as are necessary to preserve