Wouldn't "this lid" and "that pot" be more accurate?
I would think so, yes.
안 맞아요 wants a space, doesn't it?
Spacing between 안 and the verb, in the exception of 하다 / 되다, is advisable though not so important.
안 맞다, do not fit = 안맞다, misfit
안 하다, don't ≠ 안하다 = 아니하다 = 않다, not.
안 되다, doesn't work ≠ 안되다 = regretful, gaunt, poor
"this is not the right lid for that pot" flagged 12/28