The combination filled third place 12 months ago and the layers think there could be a public plunge on the Irish rider as she teams up once again with Seabass, trained by her father, Ted.
She achieved the best ever placing by a woman in 2012 and is likely to carry plenty of an estimated £200million wagered on the Aintree spectacular, which will be watched by a world-wide television audience of an estimated 600 million.
The Walsh family could well hold the key to where the bulk of the money goes as the trainer also saddles Colbert Station, the mount of Tony McCoy, while his son, Ruby, is aboard the well-fancied On His Own for Willie Mullins.
Victory for Seabass would cost Ladbrokes plenty, but they can sense a second triumph in the race for McCoy.
Representative David Williams said: “A win for Katie Walsh would be the fairytale story and could cost us a small fortune.
“But the shadow of Tony McCoy and Colbert Station looms large in the betting and we suspect it could be the champion jockey who spoils Katie’s party.
“Females will go into a fluttering frenzy for Katie and Seabass, but Tony McCoy is still the pied piper of the punters. They dance to his tune on the biggest day of them all.”
Katie Walsh is hopeful of a similar display to 2012, admitting: “I’m just hoping to get from fence to fence and if he runs the same race as he did last year I’d be over the moon.”
Speaking to Attheraces, her father, Ted, said: “When you are second in the National you are going to get 5lb or 6lb. I thought he got plenty in 6lb for being third.
“Realistically, horses of his calibre don’t win the National with 11st 7lb, 11st 8lb or 11st 9lb on their backs. Something around 10st 7lb or 10st 8lb is more likely to win it.”
Walsh is less concerned about the issue of weight for the imposing and progressive Colbert Station.
“I’ve no worry about the trip for Colbert Station,” added the trainer. “He jumps really well and maybe lacking a bit in experience.
“Colbert Station is a big power horse, weight won’t bother him and he jumps really well.
“He’s been a brilliant jumper of fences and touch wood I won’t put the mockers on him. He’s very accurate at what he does and he loves jumping.
“He’s quicker through the air than Seabass and I hope he’s just as careful.”
Nigel Twiston-Davies admits it would be the highlight of his training career if Imperial Commander can become only the third Cheltenham Gold Cup winner in history to also win this race.
The incomparable Golden Miller won the Gold Cup on five successive occasions between 1932 and 1936 and also claimed Aintree glory in 1934.
Dual Gold Cup winner L’Escargot won the National in 1975, preventing Liverpool legend Red Rum from winning the race for third successive year, although he would go on to complete the hat-trick a couple of years later.
But Twiston-Davies is confident his pride and joy retains all the old enthusiasm and ability that saw him claim a famous Gold Cup victory over no lesser horses than Denman and Kauto Star three years ago.
His talents certainly appeared relatively undiminished when he returned from a near two-year absence with a superb second in the Argento Chase at Cheltenham in January, but he missed the chance to reclaim the Gold Cup through a lung infection.
Twiston-Davies knows what it takes to win the National, having saddled previous winners Earth Summit (1998) and Bindaree (2002).
Imperial Commander will be partnered for the first time in public by the trainer’s son, Sam, with regular rider Paddy Brennan sat on the sidelines through suspension.
Asked where a victory for Imperial Commander would rank in his career, the Naunton handler said: “It wouldn’t get any better than that.
“I’m not worried about the statistics. Red Rum won it as a 12-year-old, so there’s no reason why we can’t do it.
“I think he’s as good as ever.”