Hi
I also in almost similar situation as you are but my brother is younger than yours.
There are very limited options now for immigration to UK. If you earn 75K and maybe also you or your brother have some investments, why not use Entrepreneur route?
And if your brother find a partner who has 100K, you will only need to put 100K. If you don't have this money right now, maybe your brother could come in advance and study in UK to get degree which would help him find job faster. There are good courses for oil and gas industry in Scotland or it could be business course in business school.
Entrepreneur is not cheap but there are not many other routes left. I think Entrepreneur may become more expensive pretty soon.
Does your brother enthusiastic about immigrating to UK? Is he from Russia? Udachi