Well there's a couple options other than Jarnagin, which while they're website is active and all I've heard their scaled back. You have to call them I think. That said, if Carter and Jasper will make it for you, I highly recommend them. But two other options I know of:
www.tophatssutlery.com
Top Hats can probably help you out. Their web presence is not great, but Seminole War stuff is big for them, after CW. While they're website make belt buckles and some great and useful ammo crates here in the States, their uniforms are made overseas. Give them a call or message them on FB, if you're okay with cheap Pakistani made uniforms. This weekend they're set up at the Dade's Massacre reenactment. They recently started putting out replicas of the M1828 cartridge box…
Another, I have NO CLUE if he's still in business, and I've heard things about authenticity that are off. But Mexican War stuff is a big thing for them. I've personally debated getting a wheel hat from them for my pre-war stuff.
Quartermaster Depot : Expansion Period 1825-1840's - Accessories,buttons & Haversack Makers mistakes and Used items American Civil War Western Indian Wars Spanish American war Expansion Period 1825-1840's World war II WORLD WAR II ecommerce, open source, shop, online shopping, store
www.quartermasterdepot.com
All that said, pre-war 1840's is picking up traction. I know end of the month, (I'm probably leaving later to go work on it) here in Texas near Oklahoma we're having a weekend camp out of CW Confederate cavalry and frontier Mountain Man for drill and getting ready for the Spring season. I've been slowly building an 1830's impression and Mexican War Texas Ranger impression for these fall/winter hangouts we've been doing. Feel free to reach out.
Have pics to post, but nothing does right side up now…