Thanks for the tips/info. FWIW, while the suspect valve stem was not obviously bent the tube would appear to hold air after some active 'messing around it the valve'. But I think this tube is too suspect to be used.

And it would be really appropriate if I could use mouse droppings to repair that gash

Would a 3/8" gash be considered "repairable" for future/general use of a tire?

Thanks.

dave