Your B12 looks to be fine, its just some doc's will say 300 is normal which its not, its low , jeez, it took me 3 months of B12 Cynocobalamin supplements to get my b12 score up to around 700, i think i must have been running on empty
I didn't realize how old you were but it still won't hurt to get a Glucose Tolerance done, its normaly more for people over their 40's and are overweight & don't do a lot of exercise, but there is no golden rule that fits all, its best to cover all possibilities.
all the best
Brian