For Thomas Tipper's birthplace the easiest way is to find him on the 1851 census and hope his birthplace is given, and of course that he was still alive.
FreeBMD looks like it might be unlikely that he was still alive
TIPPER, Thomas 1840 March Deaths Radford Nottinghamshire
TIPPER, Thomas 1845 June Deaths Radford Nottinghamshire
in which case it is hard, because if the information on the 1841 census is correct all you know about his birthplace is that it was outside the county of Nottinghamshire. Proving which Thomas might be your Thomas from possibilities on the IGI (which by no means has a 100% coverage) could be difficult.
If Thomas was dead by the time of the 1851 census I would check the marriage entry in 1822 to see whether it was by banns or licence. From Thomas' possible age on the 1841 census it might be that he married underage. If he did so and admitted it, then on the banns or on the licence there should be some evidence of a relative giving their permission for the marriage. Nottinghamshire marriage licences, parish records including banns, will all be held by Nottinghamshire Record Office.
For Selina if Robert's marriage isn't on FreeBMD I would check 1837online and order the marriage, or a birth certificate of one of the children. With her maiden name you can try to find her and her family in Smethwick on the 1851 census.
Regards
Valda