Qurbaani slaughter facility selling skins to a tannery

Q: I am assisting the general public in cutting and skinning the sheep as they do not have any facilities as well as many do not know how to make the slaughter. A farmer that collects skins for the tannery is prepared to collect the skins and after it has been sorted and graded at the tannery, they will then pay us some cash value of the skins.

Question: It is a generally understood common practice in South Africa for the public to leave the skins of their qurbani sheep at the slaughter facility as they have no need for it. The owners of the slaughter facility subsequently do as they wish with these skins that were left behind. If a tannery pays cash to them i.e to the owners of the slaughter facility for these skins, Can they donate it to a musjid for renovations ?

One brother claiming more from father's estate

Q: I have a question regarding hibah and wirasat.

We are 3 brothers and 1 sister, my father did all our marriages, but he spent a little more in our sister's marriage. Now my father is no more in this world, so one of my brother's is claiming that since the expenses for my sister's wedding was more, he is claiming for that much more share in the wirasat.

Kindly let me know the solution for this, does he have the right to claim more? If yes, then how much should he be given?

Note: Only 1 brother is claiming, the other 2 brothers are not claiming.

Trading one tuna for two salmons

Q: I have been curious for a while now about, "what is considered the same جنس when it comes to fish"... more specifically, can I trade 1 tuna for 2 salmons, would it be riba? Is the جنس the entire species of fish (which would entail riba) or is it in each respective sub-species, e.g. tune, salmon, yellowtail etc.?