Collecting the Half-Shekel Donation in the Temple

The Mishnah (see Shekalim 2:1, 4:3, 6:5, and 6:6 with Tiferes Yisrael ad loc.) records that there were 13 collection boxes, called shofaros on account of their long, curved necks which resembled a shofar, which were placed within the Courtyard. They were used to collect funds for the following purposes:

1. Half-shekel donation collected from the public each year.
2. Half-shekel donations owed from the previous year (which would be appropriated for different uses than the current year’s shekalim).

Both of these shofaros for the half-shekel donations were kept inside a chamber. As the donations came in, the treasurers would deposit them into these shofaros and issue a receipt to the donor. At the end of each day the coins would be transferred to a (larger) storage container also located inside this chamber.

3. Mature bird offerings (turtledoves). One who is obligated to bring a pair of birds – one for a chatas and one for an olah offering – such as a zav, a zavah, a woman who has given birth, or a metzora, may discharge their obligation by placing enough money to cover the cost of the birds into this box. The Kohanim check this box daily and make sure to bring the offerings on behalf of the owner by the end of each day.

4. Young bird offerings (common doves). One who has pledged a voluntary bird olah may place the cost of the offering in this box and the Kohanim will bring the offering on his behalf.
5. Wood for the Altar.
6. Levonah (frankincense) which accompanied most offerings.
7. Gold for vessels of the Temple.
8-13: General donations for the purchase of additional olah offerings. Each of these six shofaros was designated for a specific beis av (of which there were six) who would receive the hides of the animals offered from these funds.

Two possibilities for the design of the collection boxes: was the "shofar" 
facing up or down?