One technical aspect - the old Rolleiflex 2.8 F (the TLR) has a shutter which can be set for instant flash release "X" or for prelease "M".
Today, flash bulbs are out of use, mostly.
Please be sure to adjust the lever correctly or the electronic flash will fire before the shutter opens.
Please be aware, that the Alfred Gauthier shutter manufacturing company does only work for Hasselblad today.
Despite the fact, that I'm living only some miles away, I'm not sure, whether they do any service for legacy products.
With the knowledge of the Zeiss company politics, (Zeiss owns the Alfred Gauthier "Compur" company), I wonder if they keep spare parts on stock.
The Rollei shutter of the historical 2.8 F is quite old, so be careful!
Be especially aware of contact burn caused by high voltage/high current release of not-so-modern electronic flash lights (Metz CT line, for instance!!!) - use a modern, low voltage specimen instead - Your Rollei will say "Thank You"!
For Metz, use the current CL line, e.g.
Just a sort of joke - the modern Rollei 2.8 F (witch has no X-M lever) uses a Copal shutter, which has the direction of the speed drum reversed in comparision to the Compur shutter, therefore the Rollei people had to redesign the shutter actuating mechanism significantly.
It has TTL capability, so flash use is a charm. Fill-in is not so easy, You have to use an external meter.
The clip on TTL flash meter isn't made by Rollei any more, so You have to look on the used market for one, if You want to use a studio flash.
The SCA flash atatchement module for the modern 2.8F is made by Metz, but sold by Rollei.