Is it necessary?

[Toolman]

I purchased Billing Boats Oseberg viking ship. Is it necessary to purchase their building slip #396 to build this model.

 

[DAWarden-(Jaager)]

Is it necessary to purchase their building slip #396

As a scratch builder my perspective on this question is:
If you have already have the skills necessary or are willing to learn them, something that does the same job can be cobbled together from loose wood stock and scrap and a judicious expenditure on quality measuring tools. A beginner would have to make the "scrap". Look at what jobs a building slip needs to do. Decide if you can fake it.
You can also explore the several generic commercial building slips for sale for possible expensive alternatives.
Laser cutters have made it easy for someone looking to make back money spent on it by offering their versions of a building slip for sale.