I can't agree that it is a mixture of "finishes", it is likely as it was re-worked/re-barreled in about 1940.
The name on the bottom of the barrel is likely the re-furbisher, the E/N is the nitro proof of 1940 and the E/J is the re-work proof of the same era. Yes, it is a mixture of parts, but not in the normal sense, JMHO.
The piece is probably just like it left the work shop of the gunsmith/ re-bulder. We see others and the bigger retailers like Frankenschloss marked them with their own trademark.
It might appeal to a specialist collector of private sales/ownership pistols of the era; still not valuable - but interesting- at least to me.
