Thanks for the help, if I have success on Ebay, should have most stuff to get building. Never done a build, so should be interesting!
Last question, What bottom bracket for Sram Rival chainset, does it need to be Sram?

Just trying to source second hand parts of Ebay to build. Can I mix components, for example: Sram Rival 46/38 chainset, Shimano Ultegra cassette(12/27) and front mech, Shimano 105 shifters and rear mech.
Would it all work?

Thanks for the advice. Think I’ll buy some nicer wheels for my roadbike and chuck the 105’s onto the CX. Not sure on chainset yet, currently run 53×39 and 25×12 on my roadbike which just gets me up and over all the hills up here!

Cat as it was a sarcastic name from my football teamates, relating to my goalkeeping ability. 69 year of birth and in the uk!