It is hard to get past my anger about how badly you have been advised.
I appreciate that his behaviour may well have been bad enough that you needed to leave, but not bad enough to get an Order putting him out.
However you shoudl have been told that at that point you did NOT have to pay him anything at all and that stopping payment would NOT have any affect on your eventual settlement
In addition you should have been encouraged to move the settlement further immediately - not waiting four months for him to get the paperwork together
You should also have been told to make an immediate applictaion to the CMS regarding maintenance if he did not offer 16% of his gross income straightaway.
Finally you should also have been warned not to make a financial settlement piecemeal as you are.
You have a valid claim for spouse maintenance; as well as a pension sharing order - and those together would entitle you to a much larger share of the equity -and this will be difficult to impose once the house has been transferred.
However - that was not what you asked.
The answer to your question is that you are entitled to your share of the belongings (no mater when they were purchased) and the needs of the children are the priority - and you are entitled to go to the property whenever you wish - breaking in if necessary (provided it is before the transfer)
At this stage make a list of ALL the contents and send him a copy asking him to list what he wants in order of priority.
Tell him you will do the same and then they will be divided between you based on that list and your respective priorities.
Tell him that you WILL be taking the items that you have requested - and it is up to him to agree earlier rather than later
I hope that this is of assistance - please ask if you need further details