Is the hole spacing on an international sight base on a 1903 springfield the same as a scope base.

Too many bases to compare to . Weaver , leupold , target style etc.
But a simple answer will be if your screws are .540ish it's the same as a external adjust scope base . On 1903 a bridge mount would have 2 holes in the front receiver ring and 1 in the back . If it was for 2 piece it would have 2 screws in each .
Remember there were so many different styles of base /rings before the mostly standardized weaver , leupold varieties . These were pretty much accepted as the go to bases in the late 60s to early 70s

I was thinking of buying it if it was the right price to return it to orig or just chop it for the action. I passed.

It has international front and rear bases, no sights, it's a 1918 Springfield double HT based on the sernum and a 1944 barrel and a lengthened stock.

Have you checked to see if it was a match gun ?
The ser # should tell , I'll see if my book is close .

It's a parts gun.