".38 Military & Police models prior to the Model of 1905, 4th Change- serial numbers 241703 and under, no alphabetical prefix- have some significant differences in the design of the lockwork. Some of these guns, particularly the early ones, are very difficult to find parts for."
Yes. But given the relative number of those made, vs ones using the now common spring configuration, I think it highly likely that we're dealing with one of the later ones.
And, unless it's a Model of 1902 or earlier, I believe a set of Wolff replacement springs is a 100% replacement as the trigger return spring changed to the rebound slide style with the 1905.
So, anything post about 65,000 and we should be good to go.
And if it is a .38 Heavy Duty, as I said, springs are not a problem.