I now have in my possession, something marketed as 'big red' monitors.

- baffles aka motorboards that are a bit hackneyed.
- Mastering Labs Crossovers with seq. S/N
- 604e Super Duplex's, with UREI (non-foamed) HF horns.

What's the 'earliest' model 604 known to have UREI horns mounted to them by UREI?
Perhaps someone else has a simialr 604e for comparison's sake?
The examples that I have do not have the fit+finish that I might expect... unless the UREI conversion(s) were a bit sloppy?

*revised* pics added

thanks for any input!

Addendum (edited): Forgot to mention - the time period of the UREI horn conversions seems (seems) to be ca. 1977+, with discussion of the 604g, based on net/forum research.
The 'e' while it might have been accurate for a 'big red', may not have been accurate for a UREI conversion - thus perhaps these are someone's project... instead of something authentic?

*revised* Date code is 391522, so 1965 or 1975