How does a Ritual Caster (feat) replace their ritual book?

Question

The Player's Handbook specifically provides for how a wizard's spellbook (p. 114) and warlock's Book of Shadows (p. 108) can be replaced, but the Ritual Caster feat does not appear to address getting a new ritual book. Per the feat:

You have learned a number of spells that you can cast as rituals. These spells are written in a ritual book, which you must have in hand while casting one of them. When you choose this feat, you acquire a ritual book holding two 1st-level spells [from a chosen spellcasting class].

You can also copy additional ritual spells of the same class into your ritual book from scrolls and spellbooks, but the feat says nothing about no longer having the ritual book. (PHB, p. 169)

Can the ritual book from the Ritual Caster feat be replaced if lost/stolen/destroyed?

If replaced, does it contain any or all of the rituals in the old one?

Are either of the above dependent on the spellcasting class chosen when the feat was taken?

Answers from the core rulebooks are preferred; house rules and homebrew are appreciated if supported by experience.

Answer 1

You need to restart the process of acquiring ritual spells via this mechanic.

The process of copying the spell into your ritual book takes 2 hours per level of the spell, and costs 50 gp per level.

The feat mentions this.

When you choose this feat, you acquire a ritual book holding two 1st-level spells of your choice

This only occurs when you chose the feat.

Afterwards the content of the book, a physical object, is govern by the above. So if you lose it your only resource is to find more spells and use the above to scribe into a new ritual.

As a general comment, the general gist of the game is for the referee to present a setting for the player to experience as their character. In this sense it is a pen & paper virtual reality. This relates to your question is that given the lack of specific rules then you should consider the issue in the light as if you were really there. The Warlock getting his Book of Shadows back on page 108 is an example of a specific exception to the assumption of a pen & paper virtual reality. In this case the character has a physical book filled with ritual spells. Lose the book and you lose the spell and have to spend time and money to make a new one.

Note there appears to be no initial cost assigned to making a new ritual book. However in the equipment list a spellbooks cost 50 gp, and a blank book 25 gp. Personally I would charge them the spellbook cost for a new ritual book. However if you are not comfortable with that then charge the player the cost of a new book. Other than that there is nothing to prohibit characters from spending additional time and money to make a second backup book.

Also this is consistent with how the Wizard spell book works on page 114 which is the closet relevant mechanic.

Also of interest is that the ritual feat is the only way for a sorcerer to cast ritual spells as he doesn't possess a ritual casting feature as far as I can tell.