Depends upon the erro of MKIV you have, over time they changed a bit.
My car #85 uses a Ford bag like the earlier Cobras, off the front of the footbox. Also depends upon country of origin, US cars were laden with emissions in that space.
Later I understand they were Land Rover units with Trico pump atop, could be wrong. Circa cars in late pre-1200+ range
https://www.ebay.com/itm/135667281052?
Jaguar XKE units used as well..... 1200+ range
https://www.ebay.com/itm/29714843330...Bk9SR-7h2YzAZQ
1300+ range is what you seem to refreence, could be Ford circa 1988-1992