The IHT threshold in 1995 was £154,000. (That assumes that your husband died after the start of the 1995-96 tax year. If it was during the previous tax year the figure was £150,000). Bequests to yourself don't count against that allowance but gifts to others do.
So, if your husband left everything to you then his £154,000 allowance is transferable to your estate. However if he left £80,000 to others then there's only £74,000 of his allowance left to transfer to your estate.