Antique "Sterling" Banjolele made by Tonk Brothers of Chicago , Il. with case

Description

This item is a very cool antique Banjolele labeled “Sterling” that was made by the Tonk Brothers in Chicago, Il. , probably around 1920 or maybe earlier. I am not an expert and it was hard to find info on this so I am not sure.
It's  21" long, 7" head and the resonator measures 9".   Also  a 9” scale. 1 3/8” across the nut.   It has friction tuners , a Rosewood bridge,  ebony fingerboard and an metal flange.  I think the head is calfskin. It has cheap nylon strings on it, that were on it when I bought the instrument. I left them on because I assume the buyer will add their own strings anyway. The strings are modern and not original to the instrument,.
It comes in a neat old case that I am sure is the original case for it.
2 of the tuners slip a little but I think a bit of a tightening on the adjustment screw would fix that right up. While it is obviously used, it is really in pretty darn good condition and it is a well made little instrument .
I am not sure of the real value of it, so if you feel it is priced too high, contact me with a fair offer and I will definitely consider it.