You have been busy, Roger, but I agree with your later assessment that this one in Frome isn't "ours".
As you say, the alignment of the spire and nave is wrong: on "ours" there is a porch in what appears to be the west end of the nave (liturgical west - geographically it might be otherwise), with the spire at the NW corner. With the Frome church we seem to be looking at the east end, with the spire at the SW corner.
In addition, the architectural style is different. I know this can differ from one part of a church to another, but the large window in "ours" is Perpendicular with 4 lights (note the vertical lines of stonework (tracery) going all the way from bottom to top), whereas the Frome one is in a Decorated style with 5 lights.
Decorated is earlier than Perpendicular, and the tracery doesn't go all the way to the top of windows, instead branching out into some kind of pattern. Early Decorated, like this, has regular/cirular patterns, and is known as Geometric; later the patterns don't have circles and it's known as Curvilinear.
Arthur
