I doubt it makes any difference. The historical society seems to think they have an original piece, but in reality what are the chances this car survived almost forty years (assuming the large double door car was built in the late twenties; a safe bet) with an obsolete road name without being repainted. I think it's safe to assume that the car was relettered for the St.P. M.&M., then later for the G.N., had air brakes installed and possibly knuckle couplers, went into work service, then was later restored to the original lettering by the GN for some promotional purpose. We all know how much attention to accuracy the railroads pay when they do these restorations.

IIRC, H&B builders badges from before the turn of the century read:

Haskell & Barker
Car Company
Michigan City, Ind.
Builder

Personally, I think the note about "built by Haskell and Barker" is, in fact, something added to give a historical flavor to the old car. The reason I want to be able to read it is likely different from that of the person who posed the original request, in that I'm interested more in the historical context of the car as a '20s artifact than how it may have appeared when built or in actual early service in the 1880s.