Ask for availability against the complete confirmed contents list, with any unavailable line named and a proposed independent dispatch date. Next shipment does not answer either question
And make clear whether you have another order planned. It took me too long to realise a supplier's later could mean waiting for me to buy something else, not a parcel they were actually preparing.
Keep the installed cable out of the shortage list except as a separate clarification. Missing reserve cover and missing operating hardware mean different things to the workshop
Have they offered anything definite in response? A possible local alternative can be explored, but it should not be described as an offer from the seller or a change to the original order balance.
Does accepting the cable leave the remaining kit explicitly outstanding, and are there any added charges in that proposal? Both need an answer before you authorise it
Hazel's right. A partial delivery could still be useful, provided purchasing records what it settles and what it doesn't. I wouldn't reject the cable simply because it doesn't solve the whole kit, but I wouldn't close the whole kit for it either.
Then the identity of the required spare is established, but the proposed supplied item is not. Keep those separate while purchasing seeks the written terms; no stock or settlement change has happened yet.
That is a concrete reply to their partial proposal. Please return when those terms are answered, rather than let another next shipment message count as agreement