Can you buy new 7/8" rings that will fit For Lyman Alaskan, Texan, Weaver Etc.

New ones may be available as they are also 22mm which fit many European classic scopes. Weaver, Leupold, Redfield, Buehler, G&H, Stith all made them and they can be frequently found NIB on Ebay. Be aware of the difference between split and solid rings as the latter require "take apart" scopes like the Lyman Alaskan.
You can also buy delrin bushings from Brownells that will let you use a 7/8" scope in 1" rings.

The last, best 7/8" scope was the Leupold Alaskan that was made in 2.5, 4 and 6X.
They command huge prices today bit were never appreciated when made.