Here are 12 in stock MD compliant AR15's
https://atlanticfirearms.com/taxons/ar15-rifles?criteria%5Bavailability%5D=in_stock&page=1

Michael, I would start here Sir : blackanchorarmory.com/md-compliant-ars.html

No rifle listed.
Sounds like you already know what your looking for, but
"The following are prohibited:
✘Rifles with a capacity over 10 rounds. ✘Semi-automatic rifles with a detachable magazine and have any ​TWO​of the following features: 1.Folding stock (Not including telescoping [collapsible] stock) 2.Grenade launcher or flare launcher 3.Flash suppressor ✘Semi-automatic centerfire rifles that have an overall length of less than 29 inches. ✔ Stripped lower receivers permitted. Complete lower receivers without prohibited characteristics (above) are permitted.
“The above restrictions do not apply to rimfire rifles with non-detachable magazines.” “AR rifles not otherwise prohibited (see above) must possess a heavy-barrel contour (no cutouts).”
AR-10 type rifles are not regulated and should be transferable. AR-15 rifles featuring a heavy barrel contour are not regulated and should be transferable."
budsgunshop.com/feeds/state_reg/maryland_restrictions.pdf