Gauges
I have a 07 H-36 and had 2001 290 and the waste gauge never worked right if it even worked at all and now my H-36 very unaccurate after checking with meter said it was good and took apart and cleaned it stainless but still very inaccurate but I can open rear stern compartment and see the tank so not spending any more time or $$$$ to fix at this time.
The 290 pretty sure it's the old black plastic and horrible sensor in tank not being very good.
The fuel gauge is more important to get working and need to check all wires for good connection of gauge and sensor,the tack I am pretty sure on the 2GM is a sensor off the back of tranny.
Good luck and hope you do well and enjoy your boat,pretty sure gauges should be WEMA and go on their web ssite and they tell how to check gauges with meter.
Nick