I found a useful resource -- part numbers for the analogs of the CCT133 clutch release bearing:

QH: CCT133
KXB: KXB0376 through KXB0384
Ford: 6124271, 75BB7548BA, 80BB7548BA, 1554181, 1554191, 6052910, 6091027, 72BB7548AB
SKF: VKC2164
LuK: 500 0184 10
Sachs: 1850282640 and 3151192041
AP Borg Beck: HD 2044
Valeo: 355610
IRB: 212/175

Source: http://www.cnkxb.com/constrastmodel3.asp

Just thought I would update this thread with the Sierra spigot bearing Ford part number. It is:

Ford 1596468

I have just ordered one from my local motor factors costing £7.16 + VAT and will be here in 2 hours, quick service or what? Ford were wanting £11.96 + VAT and would take a day to deliver

The spigot bearing is HK1516 at the bearing stockists. That way might be even cheaper and available immediately. I paid under £1 for mine, as the shop had a lot of stock from a factory that went under.