Great news, and now getting used to the 'new' personality in the home... they each have their own and it will take a while for both you and the new Spaniel... they learn fast and accept change (usually). How is the Sr. Spaniel handling the situation?
The breeder had 50 breeding and retired dogs split into two clans ( roodles ?)
My dogs are of the same clan. The oldest a tricolor black-red-white was the underdog for 9 years coming second all the time ( the twin sister that died was a super dominant red)
The new dog is brown and white and subservent too
They are really trying to make out between two subservent dogs who is the least subservent and the leader of the pack

The change the new dog has to accept unfortunately

is not to get deepfreeze sheep and rice everyday
but horsemeat and chickenmeat and fish and carrots and peas etc
The only thing she dislikes is tomatoes ( which my other dogs all liked )
I guess that is because tomatoes do not smell
She has no problems with smoked salmon,shrimps,crab etc and french fries
The breeder was amazed she ran stairs ( which she never did before)
The breeder whom I know for 25 years now said she went to heaven without dying
Unfortunately he got Alzheimer and refuses to acknowledge reality of 40 dogs remaining which are
mostly "unsellable"

and his wife at 75 cannot handle everything alone