The closest anyone came to answering this question correctly was the reference to the inboard wing spoilers mandated by the CAA (one of the reasons the aircraft's entry into service was delayed for a year). Now that we actually have a C-97 flying again in 2017/2018 we will be able to see why this procedure is used.
A lightly loaded Strat can be landed on the mains but not much before the nose touches. The recent flights of 'Angel of Deliverance' were flown very light, around 89,000 lbs so landings were not much different than in a B-29, but add payload and those spoilers and longer fuselage change everything.
Also, the spoilers were never removed on any of the commercial 377 as was mentioned before. They were mandated for the civilian operators right to the end of their service lives, including on the modified Super-Strats that PAA flew. They deployed whenever flaps were lowered 10 degrees or more, and the purpose was to deflect the airflow over the inboard portion of the wing where it met the fuselage where, unlike other aircraft types, Boeing had not added a fairing. Without the fairing any sudden changes in wing angle would disrupt airflow over the inboard wing causing a stall. Early pilots (including the CAA) quickly learned that if they attempted to flare the aircraft as they would in a Douglas or a Connie the 377 would drop like a rock onto the runway. Not exactly the thing to do with tired First Class passengers after a 9-hour flight. This behavior even occurred in flight at higher air speeds with sudden pitch inputs, and it was this problem that prompted the CAA to demand the modification.
Several solutions were attempted for the nose pitch issue including a technique developed by the Air Force where anything other than a lightly-loaded C-97 would be tipped slightly to one side (usually the upwind side) and alighted on one main and the nose. This was possible because of the 3 degree angle difference between the nose wheel and the mains. If one watched old footage of the Strat or 97 you can see this technique (look for the 1951 film 'Star Lift' starring Doris Day. Rotten movie, but fantastic Stratofreighter footage!)
The problem with the dip-a-toe technique was that the airplane would then hop around on the various gear until lift was lost, less than satisfying on a cargo hop but on a commercial flight a serious source for complaints.
It was United Airlines' pilots that found a better solution with their Mainliners. They elected to carry an additional 5 M.P.H (later knots) into the landing, roll on with the nose wheel while still supported by the wing and wait for the back end to gently settle; finally a smooth solution to the flat landing attitude. United released a color promotional film in 1950 about flying to Hawaii where the technique was clearly demonstrated (and United's CEO 'Pat' Patterson nor its senior flight managers would ever have approved a film for national theatrical release with a "bad landing"). The landing, which is supposed to be at Honolulu but is actually on Runway 28R in SFO, shows the 377 gently touch on the nose and then roll right off camera--still floating on the nose. A video taken in the 80's of a cargo C-97 in Anchorage shows it touch on the nose and the pilot deliberately hold it there with a punch of smokey power before the mains come down. Look for both on YouTube.
These days this technique is often seen with NASA's Super Guppy, which has a further elongated fuselage (and everything else!) Despite having the original nose gear replaced by a shorter but tougher 707 gear the Super Guppy must rotate and land at higher speeds and often spends several seconds rolling on the nose.