What's in a lume?

Greetings, watch-people.

I've recently came into collection of an early-70s Omega (of no-name), with a 1480 movement and 166018 case. Serial is in the 33xxxxxx range. I have had many, many questions about just what it is that I have, but sadly nearly all have been answered, through several days frantically searching the OF.

I do say "sadly" because its somewhat less exciting to find humdrum answers for myself than to ask you guys and be astounded by what you tell me. (The watch turns out to be younger than I'd thought, worth rather less than I thought, and in general less novel and exceptional than I'd thought. Still a neat watch.)

A few questions yet remain though. For one:
"What is my lume?"
The dial reads "-Swiss Made-" with no T's.
When exposed to bright sunlight or UV it fluoresces and glows for 20-30 seconds and then very rapidly fades. A few minutes later the glow is very faint and shortly afterward, gone. It's a decay curve resembling that of photoluminescent paint (non-tritiated) but much shorter than the lume I've seen before.

Decayed tritium? Or oxidized/degraded vintage photoluminescent?

Anyway, happy 2019 to anyone still in the far-west timezones!

It isn’t old enough to be in the radium era (obviously) and there are no T markings (which you would see on Omega tritium offerings).....so my guess would be the latter.

Thanks!

Fairly sure it's factory. It was worn by my stepdad for some 20-odd years; by which point the crystal was badly scratched and- rather than having it replaced, my mom just bought him a new watch. My brother ended up with that (circa late-80s. gold plated or solid gold (?), in much better condition. Similar style. Original band and crown (mine had neither). But quartz movement, so a show-stopper for me 😲)

I've learned a great deal since initial acquisition; about things like "how NOT to have it serviced". And I've learned the distinction between a watchmaker and a battery-changer. The battery-changer I employed managed to order and install a new crown, but it fits poorly and is very difficult to wind. (should this be normal for a 1480 cal? I'm suspecting it's not, but have no point of reference.)

I'm wondering if it's worth the effort to take it for genuine servicing, and perhaps replacing with a genuine crown (at least one that's not so dodgy) but I'm sobered by the fact that- all in all I could easily spend several times what the watch is probably worth. If servicing the mechanism and fixing the crown would extend its lifespan by quite a few years, it may still be of use (the greater value is as an heirloom) but I'm not really clear on how much there is to gain.