Repair or replace refractory panel

[home heater]

I have a wood burning fireplace in a manufactured home. I tried to repair the refractory panel that was falling apart and the patch did not hold. So I removed the panel and found the thing was cracked .So the question is purchase a generic panel and cut to size? 150.00.
Or I was thinking of making my own out of refractory cement, about 40.00. Has any one done this? Is it worth the trouble and I am concerned about the quality of a made it my self panel.

 

[ValleyCottageSplitter]

I just got someone to come and cutout a board for $250. I don't have the masonry tools but that would be the next best option to cut it yourself. Making cement seems like a hassle and I would be skeptical of what quality you would get.

The new board is over an inch thick and it feels like a lot more of the heat is radiated back in the room.