Bill:You can probably just replace the plexiglass. I would give Bomar a call and see what they charge. You should also find out which sealant that they recommend. I think you can also get a complete replacement for the hatch if required.You can also have a new piece cut at a plastics shop and then reinstall it yourself.
I forget the exact number, but pompanette.com had the direct trapezoidal replacement for our h27. Give them a call, they'll have what you need.Also, check the photo essay on the h27 page - bet it will apply for an h25 too.David Lady Lillie