Cutlery.
Look at Kuracare paediatric or adult caring cutlery, it depends how big his hands are right now. Google for the best price, they vary enormously and also check if P+P is included.
It has fatter than usual handles and indents where his index finger will go. It also does not look like a disability aid.
Give him extra time to do tasks he struggles with, don't fluster him by chivvying him along.
Posture is important as is core strength. Can you find a cheap writing slope (thin plastic ones are economical), a knobbly wedge cushion and and something to balance his feet on if they don't touch the floor if he sits at a table or desk to write and draw?
Look at things like this so you get a good idea of how he should sit.
thebodyposture.com/sitting-positions-for-good-posture/
Can you self- refer to a paediatric OT? They can advise on loads of stuff to help him, exercises and aids. They can also check if he's hypermobile, many dyspraxics are. They can help with handwriting, advise on different grips to hold a pen/pencil. e.g www.cheapdisabilityaids.co.uk/pencil-grips-92-c.asp
How tight he holds it, how flexibly he can move it, if it makes his hand cramp or sore, if he'll need extra time in exams or a laptop instead.
Shoelaces, get Velcro everyday shoes or if not, buy special no-tie laces, loads of types online.
My DD had all of this on the NHS but that was 15 or more years ago, you may need a private OT.
66fit have a lot of products, not specifically for Dyspraxia, but things that can help and are very reasonably priced.
e.g for hands 66fit.co.uk/collections/hand-exercise-therapy
for balance 66fit.co.uk/collections/balance-training
That should give you some ideas.
We never did the EHCP, but as a parent I can assure you, you need to fight for every little thing to help your son.
Whatever you are applying for, you'll be fobbed off, sometimes repeatedly, but you have to stand firm and literally fight for his needs to be met. If you don't, he'll get nothing. It's horrible, but that's how the system is set up.
'Mild' SEN isn't a good term to use, especially when discussing your son's needs, you will be fobbed off. Keep in mind, that to be diagnosed with any level of SEN, it has to impact a child significantly.