>>I think that many internet sources say that the handle (in this case, the Moon), should be more or less opposite the centre of the bucket, >>
>>plus/minus whatever orb.
The sources are misinformed. Here's what Marc Edmund Jones says in his "The Guide to Horoscope Interpretation":
The bowl type becomes the bucket when it acquires a "handle".... When the bowl's rim in the bucket pattern is coincident with the horizon or meridian, the "handle planet" is a singleton. This will occur in many cases but not necessarily in a large number of them.... The handle planet, whether or not a singleton, reveals a characteristic and important direction of interest.... It [the bucket pattern] demands a single planet on one side, and nine on the other. The bowl section is established by the handle, and not by any defining opposition or similar consideration.
...
When the handle is situated clockwise through the zodiac, between the brim of the bowl and the vertical position, the life in general tends toward caution or self-conscious preparedness; when it lies between this vertical position and the other brim of the bowl, the life is more impulsive or inclined to respond to an immediate rather than future promise.
Jones illustrates the bucket with the horoscope of Napoleon Bonaparte, where the "handle planet has not yet risen to the vertical position". Three more several more examples (Dante Alighieri, Daphne Du Maurier, William Jennings Bryan, etc.) The handle planets are in various positions, not necessarily vertical or opposite any of the planets in the bowl.
Your example chart is most definitely a bucket pattern, with the Moon as the handle.
(I have started an educational blog, astrologysesh.com, where over time I plan to do a comprehensive treatment of astrology. I have started from scratch, and am at the point of delving into houses. In the next few weeks, I plan to get into these special chart patterns. I have the good fortune to own some great original books, including this one by Marc Edmund Jones, that will provide authentic sources for concepts that have been lost or are misunderstood.