Every known surviving Santanista musket I've ever seen, in the flesh or photos, is a post-1809 East India Pattern(sometimes mistakenly called 'third model' Brown Bess)British made musket with re-inforced cock. Each has had the lock ground flat forward of the cock and has been restamped with the Mexican 'eagle' holding a snake
marking...in all cases, the "Tower" mark has been removed as well. The gun shown here definitely has the flat side plate with tail, typical of all SLP muskets runs.
Although it's known many captured muskets from the 1835 campaigns through the fracas at San Jacinto the next April were put to some service, the number estimates have always been confusing. The night after the battle, a few arm loads were tossed on a fire as wood was scarse, unlike today's battlefield park...and yes, it can be cold in Texas in April! The resulting discharge of many loaded muskets created a rather 'exciting' few minutes among the troops and the Mexican prisoners. The one known number was from Colonel George Washington Hockley from the Ordnance Departmetn dated 18 October, 1839, and reads in part:
"The present buildings occupied as the arsenal, and originally intended for the use of the Quarter Master General, were turned over to the Ordnance Department, the number [of arms, M.J.K.] injured by exposure alluded to, were then again put into good order, including upwards of eight hundred and fifty muskets exclusive of rifles; Yeagers and Sabers, have been issued from the arms remaining after the Campaign of 1836."
A couple noteworthy things in Hockley's comments are the "Yeagers and Sabers", a definite reference to the Baker Rifles with their large saber bayonets issued to the rifle companies(light infantry) in the Mexican army of that period.
The second is the inference that many of these captured weapons appear to have been in use three years later even though Texas had received "one thousand of muskets" from Tryon, M.1816 U.S. muskets made under contract...way more than even Mirabeau Buonaparte Lamar, Texas second president, could even issue out to his imagined army. :wink: