Hoover is handicapped and has been retired as a rider. He was born with a leg deformity, low pasterns. It sounds as though he is in caring hands.
My instructor passed away the year before, so I just want to make sure I'm not going about teaching Gun wrong. Gun is a good horse, eager to please, so I don't figure he'll have a difficult time, I just don't want to mess him up. My instructor taught Hoover and I, but I'm teaching Gunner basically myself. If already his head comes down as you say - my guess is that he will teach you - all you will have to do is listen to him.
May- I'll try the circles next time I work with him...it makes sense.
I find in hand work with a new horse helps form the bond. The horse can see the handler at head height as well as hear and feel the handler. Once he follows at the shoulder on a very loose lead rein you'll know you are getting through to him
We train usually by teaching the horse it's less work if they do what we ask, never use spurs/whips/sticks. Good
In fact, I promised Hoover (he was beat with a two-by-four by his previous owner) that I would never use anything but my hand.
Sounds as though you have the gentle touch
Some owners having acquired a new horse rush into things but horses coming both from good homes and bad homes need time to settle. They have to find their place in the herd, then they have to adjust to a new routine, then they have to learn about their new owner/rider.
This chap also has to move to Western.
But my opinion is that if he has been taught over 15 years to work "on the bit" - then he will continue to seek it. So you'll have to learn how to maintain contact with the mouth without jerking it - it will take a few months to get the hang of it. As I wrote - you can still fit a western saddle and all the gear. But the Western levered curb bit with a chain is not the bit to learn on - you might inadvertently hurt him if you lose your position and jerk his mouth. At the beginning the milder the bit the better. Use both hands - move over to one handed riding later. Soft but giving hands is the most important skill to acquire.
Make sure the saddle fits - it will have a bigger footprint than he is used to - watch from rub marks towards the rump. Check the shoulder is free.
You can soon teach him neck reining but if he is well schooled already he will turn off your calf anyway.
Stopping is the more difficult issue. If you have him permanently on the bit then as he starts to speed up you can resist the movement of his neck by resisting on the reins - effectively you prevent him extending his neck.
You also resist by putting pressure down onto the stirrup bars - that's too subtle to describe in words. Watch other English riders.
Do you know if he was ridden in a running martingale? This device puts leverage and pulls the head down in times of need but other wise leaves the head/neck free at normal paces. If he tends to rush or bolt in company - you might need a stronger bit and a martingale (which can be fitted to a Western girth strap) - but you only need to use them when you anticipate mischief. At the beginning try not to hype him up.
We've debated several times "How to stop a bolting horse" on the Forum.
Best practice is until you are ready to gallop, don't put yourself in a position where he might gallop. Be careful who you ride out with.
Practice changes of pace in the arena
Work with him in the arena over poles - initially lying flat on the ground.
See if he steps or hops. Then over weeks raise the poles off the ground in 3 inch intervals. You never know he might come ready to jump those ditches.
Whatever, enjoy your new companion.
My Puddy - the Palomino - would swop from Western to English and back
According to which hat I wore. But in truth with the benefit of hindsight I was riding neither Western nor English. Back in those days 'control' was more important than 'style'. Happy days.