Sue,
I would tend to the same view as Dave Prebble, both instruments are not YET player's instruments, but from the pictures it would appear that they present no more than the 'average' standard of challenge to a competent restorer. If you can show photographs of the reed pans with sufficient clarity to see the reed details, it would help substantiate overall condition and potential.
You will have realised that the 48k is an English system concertina, my concern is that it may have brass tongued reeds. The 20k (+1 air button) is an Anglo concertina, and you will need to eventually establish the two keys the instrument will play in. Does the Anglo have any Jeffries stampings on the wood work anywhere?
Dave
Yes Dave, The concertina is marked with the name C. Jeffries MAKER. If you look on the first picture it can be seen at the top to the left of the screw on the leather strap.
Sue