One of the big thing lantern people look for is the elusive "birthday lantern" which is one which was made in the same year as you were. I've got 4 of them now, a 200A, 335, 321a and most recently a 621a.
The 621a is interesting because its an Easi-light lantern which uses a schrader valve for the shut off. It also uses an o-ring for the seal around the control valve. While we were at the Coleman convention in Ohio that o-ring failed which resulted in fuel dripping out of the control valve. On a 550 candle power lantern with a great big old mantle that scared me so I poured the fuel out of it and set it aside for the rest of the trip.
Last week I received a set of new o-rings from OldColemanParts.com. Installation was surprisingly easy considering I hadn't been able to find much information on it.
With the top end of the lantern (vent, bail, glass, burner frame, collar) removed:
The nut in the picture comes off which allows the control detent to come off and the shaft to come out:
Which reveals the failed o-ring. Looking at it on the shaft I thought that it didn't look too bad. When I tried to pry it off it broke which proved to me it needed replacing...
Here with the new o-ring:
Reinstallation was super easy, I did have to bend the control detent slightly to get the knob to engage correctly but once it was all back together it lit right up with no leak.
The lantern is SUPER bright, it puts a 237 to shame. I've got a Peerless 24A mantle on mine now, I think it would be brighter with a 111 but I hate to remove a working mantle...