Thoroughly enjoyed this and, as others have noted, not quite as fearsome as it first appeared.
The only hurdle I've yet to overcome is what the corrections to the misprints are meant to spell. I can only manage to rearrange the letters I've got in one way (7452163), but that's "an astragal moulding" according to Chambers, so I reckon I've gone wrong somewhere and must've parsed something incorrectly. Any assistance much appreciated!