A little warning when you are replacing semiconductors in B&O products.
You can find a lot of B&O products 1960 -> 1980 where some semiconductors a "painted" on the top.
This means the parts is a selected type and NOT a standard.
Unfortunately B&O do not give much information of which parameter the selection is done, but I know it can be be noise, hFE, UCE as examples.
/Frede