A Midlands version of Ditchling please

There is Mow Cap (9/10) climb, Jiggers Bank (3/10) and The Burway (9/10) also Peaslows (4/10) on this rating Ditchling is a 6/10 all in Simon Warrens 100 Greatest cycling climbs. There are a few others in there as well for the midlands.

The Burway and Wrekin are far harder than Ditchling IME

From Cannock - to the west I would look at The Burway, The Wrekin and Jiggers Bank - they are all reasonably long climbs. To the east I would look at Hanbury Hill, Woodruffe's Cliff and Marchington Cliff, these are more short sharp efforts by comparison, but you can string these together to do hill reps if you are that way inclined.

Then there is always a ride over the chase - a loop out from Cannock up to Stafford via Penkridge and Teddersley road is nice warm up, then go up Brocton Road, then over the chase and climb Stile Cop through Hazelslade then back to Cannock - there is of course always Penkridge bank over the chase - it's not steep, but it's long consistent climbing and very local - going in either direction - I would avoid peak times as it gets a bit busy with cars, but early in the morning it's a nice ride.

The Burway out of Church Stretton is pretty close - although it's actually probably harder as it's 9% for 3km - a little further than 40 miles as well, but it's a great place to ride.

Is there a reason why you need this ?

It is possible to train for climbing without the need to copy a particular hill.

Also going up Hagley wood lane is a killer if you want a challenge

Just as a rough idea : http://app.strava.com/activities/305110736

Just look towards romsley and the lickeys (no sniggering please )
Shut mill, st kenelms pass, rose hill and Bromsgrove to the top of the lickeys up the main road, winwood heath rd and there's plenty more climbs in that area. (Even a cobbled climb if you look hard enough-called the waltonberg if you look hard enough)
I know none are quite as much as ditchling but you can pack 1000m+ vertical into <30 miles if you know the area.

Probably stretching your 40 mile requirement but you might like to look at Dovers Hill, Fish Hill (a bit busy) and Broadway Hill, all around Broadway in the Cotswolds?