fixing pump and flush knob 16374 16377?

No the forum can't but I can and all it needed was a search on the net.
www.thetford-europe.com
click service, service instructions, toilets, cassette toilets select your model range then look in repair instructions book find your model. Simples.

Oh! I think you've given part numbers that's no good what MODEL is it find the model or you'll have problems of which is it in the repair instructions book.

BobUK
May 2014