yup, second/thrid gear syncros gone mate

if you are lucky it will only be the syncro rings, but from the soudn of it the teeth on the cogs may be gone too

the syncro ring slows down the gears so that it will match the rotation speeds of both, but these are made of brass and wear away easier
what you may find is that, after a while you may not even be able to stay in second and thrid as there will be nothing stopping them from popping out, then it's rebuild time, but the better option would be to rebild the box you've got spare and then get that fitted, at leat you know you'll be putting a good box back in again