Square Steinway Question

I was recently at a museum in Northern California and I was told that a square Steinway could not be tuned. Not being familiar with 19th century instruments (and being primarily a brass player), this intrigued me. First, is this true, that these instruments cannot be tuned ? Second, If true, why ? Third, If not true, are they tuned in the usual sort of way ? Fourth, what is a square Steinway (1860-1880 vintage in good condition) worth today ?

Wrong. A broken Steinway square cannot be tuned. An intact one can.

No

Yes

Nothing, or at best, very little.