This AC128 in the standard TO-1 package comes in a rather nice metallic tube that bears the words 'TUNGSRAM SEMICONDUCTORS' plus the Tottenham address, and was therefore made by 'British Tungsram', although the transistor itself is unbranded. It is a germanium PNP AF output type and is probably a Mullard device. It raises the probability that British Tungsram did not manufacture semiconductors, but just re-packaged Mullard types.
Hungarian Tungsram also made AC128, but in their typical TO-1A outline, and bearing their logo.
This is an OC1079, equivalent to an OC79 AF output driver in an outline similar to the Philips/Mullard SO-2 original. It is printed TUNGSRAM rather than bearing the logo, which raises the possibility that it was made by British Tungsram, although the construction does not look exactly like a Mullard type and the addition of 1000 in the part number is typical of Hungarian Tungsram. I would welcome information about this type.
British Tungsram changed its name to 'Tottenham Road Valve Co. Ltd.' in the early 1970s. It certainly sold some Philips/Mullard transistor types and printed 'TORVAC' on them. My image shows an OC75 printed 'TORVAC' and stored in a 4-inch tube (longer than that of the AC128 above) that is printed 'A PRODUCT OF TOTTENHAM ROAD VALVE CO. LTD., ENGLAND' but does not bear an address. I would be interested to find more such types, or any TORVAC semiconductor data literature. If you can help, please