I picked up a Rogers kit with Dynasonic. I compared it to my other 3 I have, as I am getting ready to sell the most recently acquired snare. I hope this will help to increase accuracy with dating and also further clarify what came on what snare during what era.
Observations that I've noted between the the "Oval Badge" snares with serial numbers of 19918, 33830 and 55xxx.
1. Snare 19xxx has slotted screws for all outside of the drum applications, i.e. snare guard plates, snare wire holder for butt and throw. This also had a rail assembly that didn't have the extensions on the end with the caps.
2. Snare 33xxx that I recently acquired has a combination of slotted and Phillips style screws for the above mentioned outside of the drum applications, and it did have the rail assembly that had extensions on the ends and grey plastic caps.
3. Snare 19xxx and 33xxx both have internal springs on the lugs to keep the inserts in place, where the 55xxx utilized the clip to hold them, also the first two have the snare guards that screw in place, where the 55xxx has them molded into the hoop.
4. The early versions of the Dyna shown in the Rogers book show the tension screw for the rail assembly as having a slot in the head, the 33830 and the 55xxx of mine had them too, but the 19xxx did not, but it also had the rail with no extensions.
5. Dyna #19xxx has the letter D stamped into the throw-off arm, as 33830 and 55xxx do not.
6. The 1/4 inch hex head screws that are used to secure the lugs have notches for slotted screwdrivers on the 19xxx, the 33xxx and 55xxx do not.
7. UPDATE 01-22-2012--Found a 7-line on eBay with Serial #10325. It has slotted screws for snare cord attachment and guard plates. Also had the extended arms on the snare rail
From what I've summarized from my personal snares is that to make my 19918 more "original", I took the rail assembly from the 33830 snare that had the extended rail and I put it on the 19918. As I've made sure all the outer mounting screws are all slotted, as I think the Phillips version came later.
I'm guessing at manuf. dates by estimating from what I've read otherwise.
19918-I'm gonna put this at 1967-68, strictly because I bought this snare with the kit from the original owner and the kit is Blue Strata Pearl, which was offered in 1967 for the first year.
33830-I don't remember where I got this one, but I'm going to put it about 1973.
55xxx-1975, possibly last of the Oval's in Fullerton, before the move to Big R
