Barbara- My understanding is that, in 1889, L & H started with serial number 500. There was a fire sometime in the 1890’s wiping out their records. I don’t know how high the numbers were at the time of the fire. After the fire, they started up with number 100. There was at least one more fire, possibly two, before 1910. So the early serial numbers are 3 digits, and are scrambled. There may in fact have been some overlap. The last fire, around 1909 or 1910, again wiped out the records. When they started up again that time, they went to a 4 digit serial number, and from that point forward we have all of the serial numbers.
I own Lyon & Healy 300, which has a small bust of Wagner on the column. My guess is that it dates from the late 1890’s or 1900. It has a lot of the deccorative detail found on the 23 and 22, but I don’t know if it has a model number or name. I just took the action block out and the number 300 is written on the back and below it seems to be the number 25(it’s very difficult to read). So unfortunately the early years are pretty vague.