I would replace it with steel and not fibreglass as that might not go with the aesthetic you're going for! 

@Abad MarroquinHello Abad, 5 main thing you need to do b4 placing property on market is as follows: #1: Aesthetic: Very important for units to look great and inviting.

Sometimes the minor aesthetics can make all the difference.

Also consider aesthetics and how that effects ARV.

If the AB is in good shape the vinyl is really only for Aesthetics.

Original Windows and wood floors restored to maintain the character of the home accompanied by modern interior aesthetic.

We have searched the fancy areas, and frankly, Wowzas regarding price - and not our aesthetic (very traditional, old fashioned, antiquated), it would take a lot of money to renovate after spending upwards of 1mil.

It still on very rare occasions is done, and also on rare occasions for retrofit/modification work, you may still look for opportunities to support your structure/joist systems etc with the masonry - however sometime in the early 20th century pure masonry started going out of favor, for structures being built entirely with their wood/steel, and the masonry you saw was then basically an aesthetic detail that was 'tied' to the structure holding everything up. 

These features are historic and are retained in this historic house for their aesthetics. 

Appreciation and aesthetics.