We've been through this from both sides. You need to go through the inventory from your check-in (the inventory company will provide this if you've mislaid it) and check it against his check-out report.
Are there bikes in the shed in the check-in report? No? Strikethrough!
Was the property cleaned to a professional standard when you moved in? No? Strikethrough!
In the case of the blind, if you didn't get anything in writing or mention in an email then he can potentially charge you for the blind. How old was the blind? Brand new? Don't have the receipt? Tough then. Strikethrough! If the blind was four years old, cost 30 pounds you'd probably have to pay about £8.
For example we damaged our LL's table. The table was described as high-end and an initial purchase value was set of £400. The DPS has a sliding scale which with the age of the table came out with a value of £200. We paid this. In fact, if we'd refused he would have had to have come up with the proof of purchase and shown that it was in perfect condition when we moved in, which he couldn't have done, because its condition wasn't discernible from the photos in the check-in report.
I don't have specialist knowledge but it seems incredibly unlikely that he could take you to court - the DPS will settle it (most likely in your favour).
Also, the DPS have to return the balance of your deposit immediately and only the disputed portion of it remains with them.
Good luck, don't take any settlement, you should get all your money back .