No serial number provided; no way to answer.
If you have a rimfire spur trigger model tip up model,than you have a model 1 1/2 second model which was made from 1868-1875.If you have a centerfire model 1 1/2 then it was made from 1878-1892.You may also have a model 2(old army .32cal rimfire tip-up)which was made from 1861-1887.This is based on the serial number that you supplied,and a limited description of the firearm in question.
Manufactured by Iver Johnson and sold by J.P. Lovell Arms. The Defender were made from 1875 to 1888 and the Defender from 1889 to 1895. .22 short r.f. caliber, 7 shot single action Defender no 1 revolver, spur trigger, solid frame, 2 1/4" round barrel, fluted cylinder, birdhead grips, walnut or checkered black rubber, nickeled, marked DEFENDER .32 short r.f. caliber, 5 shot single action Defender no 2 revolver, spur trigger, solid frame, 2 1/2" round or octagonal barrel, fluted cylinder, birdhead grips, walnut or checkered black rubber, nickeled, marked DEFENDER .38 short r.f. caliber, 5 shot single action Defender no 3 revolver, spur trigger, solid frame, as above .41 short r.f. caliber, 5 shot single action Defender no 4 revolver, spur trigger, solid frame, as above In 1882 they were sold at Defender no 1 = $1.50 Defender no 2 = $2.85 Defender no 3 = $4.10 Defender no 4 = $5.60 .22 r.f. caliber, 7 shot single action revolver, spur trigger, solid frame, 2 1/8" to 2 1/2" round or octagonal barrel, fluted cylinder, birdhead or square butt checkered black rubber grips, nickeled, blued or case hardened on in combination of that, marked DEFENDER 89 (improvement introduced in 1889) .32 r.f. caliber, 5 shot single action revolver, spur trigger, solid frame, 2 1/8" to 2 1/2" octagonal barrel, fluted cylinder, saw-handle square butt checkered black rubber grips, nickeled, marked DEFENDER 89 (improvement introduced in 1889)
No published data.
That patent date appears on the H&R Model 1 revolver, which is a spur trigger single action in either .32 rimfire or .38 rimfire. Value can reach $200 or slightly more in top condition. sales@countrygunsmith.net
Iver Johnson $150
Is the H&R a 5-shot spur trigger revolver chambered for the .38 rimfire? If so, my guide suggests $75 in Poor condition and $200 in Excellent. The Blue Book lists the H&A for $45 in 60% condition and up to $140 in 100%.
Liberty was used by several makers. The more common ones that look a bit like the Colt Peacemaker were imported by Liberty Arms, but made by Herbert Schmidt in West Germany in the 1960s. There is a a much older Liberty made by (IIRC) Norwalk, unfluted cylinder, spur trigger, no loading gate, no trigger guard, usually nickel plated- THOSE date from the 1880s or so.
Cervicogenic Headache is the headache type usually caused by a cervical spur. However, cervicogenic pain can trigger Migraine in susceptible individuals. For diagnosis and treatment of your headache, seek the help of a headache specialist in your area.
You must have a more in-depth reference on Iver Johnson than I do if you are getting terms like "early 2nd model". Their spur trigger revolvers are worth $25 to $150, depending on condition. The later models with trigger guards, $25 to $250, depending on condition and exact model.
If it is not marked on the gun, you will have to measure it. The most probably calibers for an H&R revolver are .22, .32, and .38. A standard lead pencil will not go into the barrel of a .22, fit fairly well into a .32, and be loose in a .38, but don't run out to buy ammunition based on this estimation. Let a gunsmith or experienced dealer see the gun and recommend the proper ammunition (or recommend that it not be fired at all!). That patent date, alone, appears on the H&R Model 1 revolver, which is a single-action revolver with bird's head grip and spur trigger. It was chambered in both .32 Rimfire and .38 Rimfire. The ammunition is obsolete. sales@countrygunsmith.net
Spur
What is spur formation?