There is a small museum at Wat Phra Si Rattana Maha Tat. That is the most famous temple in Phitsanulok. The museum is called NATIONAL MUSEUM PHRA BUDDHA CHINNARAJ. If you go to the temple, near the river, the museum is free and there are some nice pieces inside.
Here's a 360 picture of it:
360.io/m9NaBr
This is made of pearls, in 1873, used by monks.
And this is a bowl from 14th century.