realeswatcher Your semi-observant eye is fairly accurate. The most common dates (based on raw numbers) are 1832, 1834, and 1842.
Close contenders after that are 1829, 1830, 1836, 1838 and 1844.
Even dates outnumber odd by a wide margin. (No reason they just do).
There are a few Riddells that are scarce to common and appear at least one time a year on
ebay. That list is:
221 1829 Zs AO
223 ZS OM dates 1830, 1831, 1832, 1833, 1834
237 Zs OM dates 1834, 1842 (Two varieties A,B)
246 1835 Zs OM
247 1836 Zs OM
274 Zs OM dates 1836, 1842
279 1843 Zs OM
302 Go MJ dates 1832, 1834
314 1834 Go PJ
324 Go PJ dates 1834, 1835, 1836, 1837, 1838, 1839
350,351 Do RL dates 1826, 1827, 1838
365 Do RM dates 1832, 1834
371 Do RM dates 1832, 1834
373 1836 Do RM
377 1839 Do RM
404 1838 Ms OM
406 1827 G AO
412 1840 G PJ and G J
417 1836 Ds RI
Of these there are 5 that are common
233 1832 and 1834 ZsOM
237 !834 and 1842 Zs OM (A variety only)
274 1834 Zs OM
371 1832 Do RM and mules
374 1834 Do RM and mules
Overall these 5 are also the most common including even the non-Riddells.
The 371/374 family is overall the MOST COMMON forgery type that exists. There are 2-3 per month on average. It is also a hubbed die family with several die varieties. It is a fun family because of interrelated matings that I am still actively working on.
The 237 is the second most common of all counterfeits coming up every two months or so but has the widest range of alloys of any of the contemporaries. It is also my favorite counterfeit because it was my first. I am approaching 100 copies of that Riddell # in my own collection because I collect it by alloy, striking variety, and die state. I even collect by cancellation method. But I do not buy every one I see. I pass over 2 out of 3 because there is no difference by my criteria.