The source explains (citation, 10 November 2017):

We announced in our previous release that we were planning to stop the publication of Turnover and Orders in Production and Services Industries (TOPSI), which is based on the Monthly Business Survey (MBS). [...] From December 2017, the Index of Production and Index of Services bulletins will each contain an additional annex covering the Monthly Business Survey data used in the compilation of that bulletin.

In response, we have:

• Marked the TOPSI catalog node as discontinued.
• Appended a new subnode to "Index of Production" for its MBS annex.
• Appended a new subnode to "Index of Services" for its MBS annex.
• Changed the "source" metadata on each series to "Monthly Business Survey (MBS) turnover in production industries" or "turnover of services industries" as pertinent.

The corpus of transplanted series is:

• MBS production industries: 109 concepts at each of three frequencies
• MBS service industries: 30 concepts at each of three frequencies (31 monthly)

Properties are otherwise unchanged. Figures are millions of British pounds (Mil. GBP) not seasonally adjusted (NSA).

The series related to production industries reside in the historical catalog (United Kingdom » Industry » Index of Production » Turnover and Orders in Production Industries (MBS annex)) and include, for example: 

• ONSJT27A.IGBR_X = Balance - Total turnover for manufacturing in the UK [C] - for Great Britain
• ONSJQ4JQ.IGBR   = Imports - Processing and preserving of fish; crustaceans; molluscs; fruit and veg [10.2 to 10.3] - for U.K.
• ONSJQ7CM.IGBR   = Exports - Petrochemicals [20B] - for U.K.

The series related to services industries reside in the historical catalog (United Kingdom » Industry » Index of Services » Turnover and Orders in Services Industries (MBS annex)) and include, for example:

• ONSJQ2NA.IGBR_X = Balance - Wholesale trade services; except of motor vehicles and motorcycles [46], (Mil. GBP) - for Great Britain, (Mil. GBP)
• ONSJQ37Q.IGBR_X = Balance - Food and beverage serving services [56] - for Great Britain
• ONSDYQOM.IGBR_X = Balance - Postal and courier activities [53] - for Great Britain

Because catalog locations are subject to change, the upper-right search box on DataBuffet.com provides a "find in catalog" mode that accepts a mnemonic.