New SeaCraft Owner

[Halfshell]

Hello,
I have just added a boat to the fleet. It is a 1975 20' with a 165 Mercruiser I/O. The boat appears to be in good shape with respect to the normal worries and researching topics on this website prior to buying has been a huge asset. I have a couple of questions and I hope someone might know the answer to or have an opinion on. The first is...How is the fuel tank (Under the Console) installed in these boats. Foamed..? or something different. Also, this model has the helmseat as a pad on the Motorbox since there is no room between the console and the motorbox for pedestals. Has anyone with a similar layout installed seats on the motorbox or fabricated some kind of backrest. Insight / opinions appreciated. Thanks very much.