Can anyone confirm what year had the indicator to the side of the headlight switch and wiper switch as seen on the bezel pictured below. I recall it being a 1974 thing but couldn't remember for sure.

Late 71, nope.

the change in the bezel (additional WIPER & HEADLIGHT symbols) was for model year 1974

from the Parts Catalogs:
8-37-90 BEZEL, speedometer & instrument cluster
Plymouth & Dodge B-bodies (RW)
rallye:
w/radio
2985 158 (1971-'73) & 3592 686 (1974)
w/o radio
2985 157 (1971-'73) & 3592 685 (1974)

Any chance they could come on a late 73 or not so much?

I've always heard '74 only.
You may want to post your question
on www.roadrunnernest.com

you'd have to look for other similar date late-'73s from the same plant

so, what plant & how late?

no offence to other sites, but there have been what <10 threads & ~40 posts since the first of the year

Here's a picture of the part number on mine, the same part number as the one listed on page two of the for sale section here which does not have the indicators. Maybe there's another number on mine I missed? I'll have to check. FWIW, I still think your right about being a later application. Just not sure about the possibility of a late 73 application yet.

Here's a screen shot of the one listed for sale, as mentioned above for reference...