When they built North Hull Estate after WW2 wood was in short supply so they used owt they could get their hands on that came through the docks, some of it as ballast or packaging. They weren't fussy.

Late seventies the council decicided to replace all doors and windows with softwood. Mate of mine who was also a woodturner described it as wanton vandalism. Most of the frames were mahogany or various rosewoods, he collected enough scrap wood to keep him and his turning friends going for years but most was just burnt. There were decades of use left in them. The doorframe of my garage is three pieces of iroko from the same source and it's fine nigh on 30 years later.

The softwood replacements were replaces under a decade later.

All the best

Steve