Citroen Specials Club - the club for all lightweight cyclecars

I am trying to change my engine, which I foolishly thought would be quite a simple procedure for a 2 cylinder engine mounted in front of the gearbox.
How wrong was I !
First problem I encountered was that the front chassis cross member is fixed !
Is this normal?
After discovering this, I decided to lift the whole engine and gearbox up a couple of inches and prop the gearbox underneath across the chassis.
This is where I encountered my next problem, I can only see 2 11mm bolt heads which are holding the gearbox to the isolastic mounting to a "swan kneck" shaped bracket welded to the top of the steering tube.
As far as I can see these 2 bolts are all that is holding the gearbox and engine onto the chassis at the rear.
Am I correct in that assumption?
How difficult/easy is it to remove/replace these 2 bolts in order to raise the engine/gearbox assembly sufficiently to slide the engine off the gearbox shaft ?
If anyone knows about this particular issue I would appreciate any/all help that might be forthcoming.
I am kinda stuck at the moment and reluctant to remove the 2 rear mounting bolts as they are quite tight and in a really awkward place to get at for removing, let alone replacing.

You can usually take the engine out by lifting engine up still attached to gear box high enough to clear the front cross member then put something across the chassis to support the gearbox then after removing the four nuts on bell housing just pull engine straight forwards off the gearbox. If you are taking gearbox and engine off together you can undo the 2 x. 11mm bolts you’ve seen at the rear of the gearbox box to remove together but when you replace box/engine I would put them in first and tighten the big bolts last ..

Thanks very much mate, that's just what I needed to know
I am only swapping the engine so the gearbox can remain bolted in place without the need to remove any of the bolts.
I was a little worried that it might put too much strain on the isolastic mounting,
( always assuming that the rubber mounting isn't perished or damaged)
but if you say it's common practice to lift the whole engine/gearbox as one, prior to supporting the gearbox across the front chassis rails, then that's what I'll do.
Then I'll reposition the car under the hoist and fit the sling to the engine to take the weight, then remove the 4 large bell housing nuts.
In 'theory' the engine 'should' slide off the gearbox shaft and 'hey presto' lower it to the floor!
Does that sound about right?

Ref gearbox mount fixing bolts, on my 223 I put 2 holes in the front bulkhead aligned to the bolt heads.
This enabled access for a socket onto the bolt heads - much easier than trying to work on them with a spanner in the engine bay!

Hi.
On the occasions I've removed an engine I've done it complete with the gearbox. Loosen the two M10 (17mm hex) bolts which attach the isolastic mount to the gearbox, detach from engine mounts, electrics and gearstick swivel and up she comes.
I've read somewhere of someone not re-tightening the M10 sufficiently and the gearbox leaving the mount under braking 😅. Not good!