The rifle is an Arisaka Type 99. It looks to be mid-war, judging from the lack of airplane sight "wings" on the rear sight coupled with the presence of the front sight ears. If you look on the left side of the receiver, there should be (from left to right) a series Kanji (mark), then a serial number, then the manufacturer's Kanji. The pictures are not clear enough to make out the arsenal and series marks. But judging from the stock, I would guess the arsenal is probably Nagoya. Look on top of the receiver and it will have one hole, then Japanese characters underneath (that identify the rifle as a Type 99). Above the hole, it should also have a Chrysanthemum, unless it has been ground off or defaced. Also, check the screws on the rifle. They should all be punched/staked in place if it has not been messed with.
Check the bolt handle for the last 3 digits of the serial number and see if they match the last 3 digits of the receiver - if so, it should be the original bolt. These rifles were given to servicemen in the Pacific as souvenirs by the tens of thousands at the end of the war and it was not uncommon for the transport ships to require the soldiers to remove the bolts when boarding and throw them in a barrel for the voyage (to make sure there were no accidents). When they got off the ship, they walked by the barrel and reached in and grabbed one on their way off. As a result, bolt mismatches are very common on Type 99's.
I know nothing at all about the knives.