Hi DM & welcome to the forums.....I've seen your threads about Doodle pop-up frequently lately, so decided to take a look see, so did a quick read-through of your posts & realistically, I think you might as well plan on a extended coming around period.....
With brand new birds, birds that may have been hand-fed, but not hand-tame, it can take as much as six months to hand-tame a bird! For previously owned birds, almost anything is possible, as has been mentioned. Over the past several years, some 20+ birds have crossed our threshold...all conures or p'lets and in all forms of tameness. When you rehome a bird with baggage, it can be a daunting task trying to overcome that baggage, but I've always had the benefit of a couple of other birds around when newcomers come to perch.....I think my most challenging converts were essentially wild sibling sun conures of two succeeding clutches that had been parent raised and caged together after the parents kicked them out of their nest cage.....when I agreed to take them, I brought them back to Georgia from Massachusetts and put each of the four of them into individual cages & just tuned out their continuous displeasure with being separated. Since they were essentially wild, I started with giving each sprigs of millet & a few peanuts.....this went on for about a month while everybody kind of settled in and the separation screaming started turning into the morning & evening flock calling, then I stopped the millet & peanuts from their diets, waited a week & started evening teases, opening the cages for my other birds, but leaving the gang of four caged...everybody was out but them...some of my guys climbed up on their cages & three would fly to my shoulder & hang out, then when it was time for bed, I'd put out a communal bowl of some cut up millet sprigs, then I'd make a very obvious display of giving each bird a peanut kernel half, then an again obvious display when each got the remaining half.....this went on for a couple of weeks, when I finally let one of the gang of four out, sat at my desk, pulled a peanut half out of my pocket & held it up.....you could see the wheels of decision turning & concerted squawks from the other three when she flew to my upheld hand, pluck the nut, but flew back to her cage when I moved my hand.....this went on with all four suns for about another month while they wrestled with their individual security problems...they were becoming much more independent and no longer really relying on their siblings for strength.....
All in all, it took almost a year to get them all hand-tamed to a point where I felt comfortable finding them new homes.....on the flip side of this story, I've had several birds cross our threshold that were easier to work with, but they can take much more than the proverbial steak and scratch behind the ear that would make your puppy a friend for life.....
You've received good suggestions, but each bird is an individual & without knowing Doodle's background, you almost have to start from square one.....just try to not be too pushy in your frustration.....
Good luck.....