Maybe a good 20 years ago. Was after formation of MRL. When BN/MRL and LMX powered the trains. It was during the time that I had relatives living in Helena.
Talking with another NP man, he says that BN replaced that NP marker, as shown in what I emailed to you. He says that "P" is definitely a permissive marker, but he does not remember it and that it seems too small.
Would be nice also, if it had some other marking on it, that might help ID when(timeframe) and/or where(location) it came from! At least it has been positively ID'd as a Permissive Block marker. Have a couple of other forums I can try asking through. Maybe someone else can ID the thing better? Not an absolute necessity, but worth a shot.
I found my 1980 CCOR. In the BN section, it shows their signal markers. Size unknown, but they are round and square. They are painted a yellow background, with a black letter. If this is a signal marker, which it would seem to be, I've got to guess it is somehow from the NP era.
Is it possible, that it's not NP or BN, but maybe GN?? I kinda doubt it, but just throwing another possibility out.
If so, it would have been carried in and dropped somehow. The GN came in roughly the north side of Helena, and this is well west of the Capitol. The center of the Tunnel up there is twenty miles west of Helena. I found a page which shows a very few MRL symbols. Nothing close to a match there. MRL took over operations of that line in 1987.
Pulled out the DRGW Standard plans I've got and checked. Does match the Grande either. Their signs were 12", with beveled corners. And had 8" letters. Have a couple of forums to check yet. So, I'll try those next.
